ASAP (As Soon As Publishable)

Developing efficient and inexpensive bifunctional electrocatalysts for the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) is essential to promote the application of metal–air battery and fuel cell technologies. In this study, the ORR and OER catalytic activities of a Co single atom embedded in different positions of the hexagonal graphene-like boron–carbon–nitrogen (h-BCN) material to form various types of Co single-atom active sites have been comprehensively and systematically investigated by using density functional theory (DFT) calculations. The adsorption properties of different active sites on the h-BCN surface for oxygen-containing intermediates during electrochemical reaction processes are calculated, obtaining h-BCN with Co single atom (Co@h-BCN SACs)-embedded materials exhibiting superior ORR and OER catalytic activities. Theoretical calculations and analyses of the structure, electronic properties, and reactivity characteristics of Co@h-BCN SACs show that Co@h-BCN SAC-2 possesses excellent bifunctional catalytic activity, with ORR and OER overpotentials of 0.51 and 0.46 V, respectively. In addition, Co@h-BCN SAC-7 and Co@h-BCN SAC-8 also exhibit good ORR electrocatalytic performance with ORR overpotentials of 0.49 and 0.43 V, respectively. This study reveals that embedding a single Co atom into the h-BCN lattice results in the formation of multiple catalytically active sites, and only the appropriate positions have efficient ORR and OER catalytic activities. These findings facilitate the rational design of Co-embedded h-BCN materials for highly efficient OER and ORR electrocatalysis.

This work elucidates the design, synthesis, and characterization of Ag_MOC-1, an Ag(I)-based metal–organic cage. Crystallographic analysis reveals trigonal coordination of Ag with a large void and a high Brunauer–Emmett–Teller surface area of 172.8 m²/g. Ag_MOC-1 exhibited an excellent Tafel slope of 74 mV dec^–1, indicating faster kinetics via the Volmer–Heyrovsky mechanism. Computational calculations attribute accessible Ag-site favored by porous morphology-driven H* adsorption with a near-optimal hydrogen adsorption free energy (ΔG_*H) value of −0.02 eV, endorsing excellent electrocatalytic hydrogen evolution. Ag_MOC-1 displayed good activity and stability over the period of 3 h. However, on prolonged operation, controlling potential electrolysis at −0.51 V (V vs RHE) for 24 h revealed the structural and morphological transformation of Ag_MOC-1 to corresponding catalytically active Ag₂O species, as justified through powder X-ray diffraction, FT-IR, SEM, and EDX analysis. Analytical, morphological, and computational analyses consolidate that the synergistic interplay of tailored porosity and accessible Ag-active sites for efficient hydrogen evolution reaction (HER) offers promising insights into the development of next-generation HER materials.

Designing highly efficient, environmentally friendly, sustainable, and durable catalysts for water electrolysis is vital for advancing renewal energy systems due to the continued reliance on fossil fuels leading to energy shortages and rapid environmental pollution. In this work, we have synthesized a tetranuclear centrosymmetric, unusual azide-bridged (end-on) Ni^II₄N₄O₂ defective dicubane core with all hexacoordinated nickel(II) atoms via a simple slow evaporation method. [C₄₂H₅₀Ni₄N₁₆O₁₀] (Ni₄-cluster) has an orthorhombic crystal system with space group Pbca, distorted octahedral of each nickel center to the formation of a tetranuclear nickel cluster. Single-crystal X-ray diffraction (SCXRD) analyses reveal that the cluster is tetranuclear with μ₂-(1,1-azido) and μ₃-(1,1,1-azido) bridges. The Ni₄-cluster shows a highly active and stable electrocatalyst for hydrogen evolution reaction (HER) in a 0.25 M acetate buffer electrolyte (pH = 3.8), achieving a low overpotential of only 287 mV at 10 mA cm^–2 current density, with high double-layer capacitance (C_dl) (0.34 mF cm^–2) and low charge-transfer resistance (17.6 Ω). The intrinsic parameters such as Tafel slope (316 mV dec^–1), turnover frequency (TOF) (1.82 s^–1 at 350 mV), and exchange current density (0.002 A cm^–2) correlate to the fair electrocatalytic activity of the Ni₄-cluster cathode for the HER. The electrode remained stable for over 25 h at a constant current density of −10 mA cm^–2. The Ni₄-cluster delivered over 92% Faradaic efficiency for hydrogen production in the 0.25 M acetate buffer electrolyte. Compared all the electrochemical analyses, the Ni₄-cluster reported that it is more active, efficient, and sustainable for H₂ production and makes it an auspicious candidate in the field of energy conversion application.

Over the past decades, nanomaterials have enabled battery materials to achieve rapid redox kinetics comparable to pseudocapacitive materials due to the shortened ion diffusion length and high surface/interface exposure. Consequently, the boundaries between pseudocapacitive and battery materials have become quite blurred, and the distinction between the two concepts has become unclear. Typically, nickel/cobalt/nickel–cobalt sulfides/selenides/phosphides are widely reported as active materials for supercapacitor applications in an alkaline electrolyte. They are described as pseudocapacitive materials despite exhibiting electrochemical features similar to those of battery materials. Therefore, in this work, the electrochemical behaviors of nickel–cobalt sulfides/selenides/phosphides are systematically and comprehensively analyzed. We demonstrate why it is inappropriate to describe them as pseudocapacitive electrode materials in an alkaline electrolyte. This paper does not discredit the extensive experimental work conducted within the realm of pseudocapacitance but aids in comprehending the distinctions between pseudocapacitive and battery materials more thoroughly, thereby avoiding the definition confusion. More importantly, this clear differentiation will enable the rational selection of material classes and corresponding structural engineering approaches tailored to specific application requirements.

In photocatalysis, single catalyts often face issues such as low photogenerated carrier separation efficiency, high carrier migration resistance, and catalyst system instability, which result in low photocatalytic hydrogen production efficiency. To overcome these challenges, researchers commonly employ cocatalysts. In this study, MnCdS was coupled as the main catalyst with NiTiO₃ as the secondary catalyst to adjust the migration trajectory of photogenerated carriers and inhibit their recombination. This study investigates, through experimental analysis, the mechanism by which introducing the cocatalyst NiTiO₃ improves the yield of hydrogen evolution catalyzed by MnCdS during light irradiation. The final experimental outcomes demonstrate that NiTiO₃ nanoparticles were successfully anchored onto the surface of MnCdS clusters via surface modification, resulting in the formation of a type II–II heterojunction at the interface between the two materials. The establishment of this type II–II heterojunction induced the directional migration of photogenerated charge carriers to distinct regions within the interface. This divergence in migration paths facilitated the spatial separation of photogenerated electrons and holes, effectively mitigating their recombination within the same catalytic system, and ultimately enhancing the hydrogen evolution efficiency.

While sulfide-based all-solid-state batteries (ASSBs) have drawn significant attention due to their inherent safety and potential for high-energy-density cell designs, their performance is often hindered by various heterogeneities within the cathode. Unlike conventional lithium-ion batteries (LIBs) with liquid electrolytes, ASSB cathodes rely on solid–solid interfaces between cathode active material (CAM) particles and solid electrolytes (SEs), leading to challenges that previously have not been dealt with. This review examines cathode heterogeneities across multiple length scales─interface, particle, and electrode─focusing on how they are formed and lead to performance degradation. Additionally, we discuss various approaches that have been developed to mitigate these issues such as modifying fabrication methods, adjusting particle sizes, and inventing electrode structure designs. By addressing these challenges and strategies, we aim to facilitate further advancements in ASSB technology, paving the way for scalability and commercialization.

Benefiting from the flourishing development of polymerized small molecule nonfullerene acceptors (PSMAs), the performances of all-polymer solar cells (all-PSCs) have made significant progress. The dynamics of excited states, as the intrinsic factor determining the upper limit of the power conversion efficiency (PCE), is still obscure like covered with a veil. Therefore, it is extremely urgent to investigate the correlation between them. In this perspective, PY-DT is chosen as the PSMA, in which L8-BO acts as the counterpart. The results demonstrate that the properties of intramoiety delocalized states (i-DEs), a connecting link between the preceding and the following states, are related to the process of hole transfer and charge separation (CS). Thus, the longer lifetime of i-DE in the D18:PY-DT device contributes to less nonradiative recombination triggered by the formation of a triplet state (T₁). However, the entanglement among chains of PY-DT decreases the miscibility of the polymer donor (D18), resulting in severe aggregation and radiative recombination. The results highlight the influence of i-DE properties on the performances of all-PSCs, providing enlightenment for the design of high-performance PSMAs.

The thermoelectric performance of polycrystalline SnSe remains significantly inferior to its single-crystal counterpart due to grain boundary scattering, which limits carrier mobility and electrical conductivity. Herein, we present a strategy employing AgGaSe₂ as a second-phase dispersion within the SnSe matrix. All specimens in this manuscript were synthesized via high-temperature melting method, with thermoelectric properties measured along the in-plane direction. The as-prepared SnSe-AgGaSe₂ materials exhibited characteristic p-type semiconducting behavior. This approach enhances carrier mobility, optimizes the power factor, and significantly reduces lattice thermal conductivity through intensified phonon scattering. Consequently, the (SnSe)_0.99(AgGaSe₂)_0.01 sample achieves an ultralow lattice thermal conductivity of ∼0.24 W m^–1 K^–1 and a peak ZT of about 1.41 at 773 K. This study presents an innovative single-modification strategy that simultaneously optimizes electrical and thermal transport properties, providing a direction for improving the thermoelectric performance of polycrystalline SnSe.

The electrical transport properties of nano SrTiO₃ were systematically investigated under high pressures up to 24.5 GPa using AC impedance spectroscopy and first-principles calculations. Through these methods, we identified and elucidated the underlying physical mechanisms responsible for the cyclic ion–electron transformation. This phenomenon arises from variations in C-axis compressibility and a phase transition from the cubic to tetragonal structure, which induces abrupt changes in electron density around oxygen atoms. By applying pressure, it becomes possible to control the lattice spacing, thereby modulating the charge density of O ions and enabling a smooth transition between ion and electron conduction pathways. This study deepens our understanding of the cyclic transformation of ion–electron behavior within solid electrolytes.

Silicon-based anode materials are regarded as an ideal choice for high-performance lithium-ion battery anodes because of their high specific capacities and abundant resources. Carbon coating is an effective strategy to mitigate their significant volume expansion, but some carbon materials have low mechanical strength. SiOC has high chemical stability and mechanical properties, which can make up for this weakness. Here, we report a simple SiOC coating method for Si nanoparticles prepared from the in situ condensation of phenyl-POSS (polyhedral oligomeric silsesquioxane) and subsequent carbonization. POSS disperses well and forms a uniform and dense SiOC coating after polycondensation. Its cage structure creates pores that help buffer silicon expansion and provide more pathways for lithium-ion transport. SiOC formed by phenyl-POSS has a high carbon content which gives it excellent electrical conductivity, and its rigid cross-linked network between phenyl groups can effectively limit silicon’s volume expansion. The optimized sample has a high reversible capacity of 985.0 mAh g^–1 at 0.5 A g^–1, and it still remains 866.7 mAh g^–1 with a retention rate of 90.1% after 200 cycles. The excellent electrochemical performance demonstrates that phenyl-POSS has great potential as a coating material to boost the structural stability of silicon anodes, offering an approach for utilizing phenyl-POSS in electrochemical applications.

Anode-free lithium metal batteries (AFLMBs) show significant potential for next-generation energy storage systems. However, the lifespan of AFLMBs is constrained by continuous parasitic reactions between lithium and electrolytes and the generation of dead lithium. Here, we design a local-high-concentration polymer electrolyte (LHCPE), which is composed of a poly(1,3-dioxolane)/poly(vinylidene fluoride-co-hexafluoropropylene) polymer blend and LiFSI salt. The distinct anion-rich Li⁺ solvation structure in LHCPE induces an inorganic-rich interface, which can suppress Li dendrites. The additive of tin trifluoromethanesulfonate (Sn(OTf)₂) is incorporated into LHCPE to mitigate nonuniform Li deposition through the formation of a CuSn alloy layer on the current collector. The developed electrolyte shows remarkable cycling stability of AFLMB (Cu-NCM811), maintaining 50.9% capacity after 50 cycles at a cutoff voltage of 4.5 V. This strategy is promising in the design of polymer electrolytes for anode-free batteries.

Fast charging is a key requirement for next-generation lithium-ion batteries (LIBs). Yet, conventional polyolefin separators often suffer from poor electrolyte wettability and interfacial compatibility, limiting the charging performance of LIBs. In this study, we introduce an effective approach to overcoming these challenges by utilizing the amphiphilic nature of long-chain polyamide 1012 (PA1012) to prepare high-performance separators. The membranes of PA1012 are fabricated using a facile method, i.e., Mixed ‘Non-solvents’ Evaporation Induced Phase Separation (MNEIPS), allowing membrane formation within 1 min. The presence of polar amide groups in PA1012 enhances the electrolyte wettability and ionic conductivity, which significantly improves the rate performance and cycle life of LIBs when applied as separators. Our findings provide fresh insights into the application of long-chain polyamides in advanced energy storage systems, paving the way for the development of high-performance, fast-charging LIBs.

The hydrolysis of bulk porous aluminum (Al) allows the production of hydrogen. However, in water, the yield and kinetics of the hydrolysis reaction are very low. In this study, in order to overcome these problems, the hydrolysis was carried out in a NaOH solution to eliminate the passivation phenomenon. Al materials were fabricated using uniaxial hot pressing that allows control of the relative density of the fabricated materials. The role of the porosity rate on the kinetics of the reaction was investigated. The results showed that the relative density rate significantly influenced the rate of hydrolysis; lower relative densities led to a faster reaction speed. Complete hydrolysis (i.e., 1245 mL/g of Al) is reached after 50 min for the 50% relative density sample, whereas it takes more than 300 min for the one with 90% relative density. A correlation between the microstructure and hydrolysis behavior exists. Two models were applied to highlight the reaction mechanisms. Hydrolysis at various temperatures allowed the determination of the activation energy of the reaction, which was found to be almost constant, whatever the relative density rate (i.e., Ea = 50–55 kJ/mol). The reactions were found to be primarily controlled by the surface.

The commercialization of Li-rich Mn-based cathode materials (LR) is hindered by structural instability, voltage decay, and poor cycle performance. To address these challenges, we propose a cost-effective composite cathode material (LRLFP) by integrating LR with structurally stable LiFePO₄ (LFP). The composite leverages a cooperative shunting mechanism: during high-rate discharge, current preferentially flows through the highly conductive LR component, ensuring high specific capacity, while LFP mitigates electrolyte erosion and stabilizes the interfacial structure. The LRLFP composite delivers discharge capacities of 211.3 mAh g^–1 (0.1 C) and 139.6 mAh g^–1 (5 C) within 2.0–4.6 V, with 92.55% capacity retention after 400 cycles at 1 C. At 55 °C, LRLFP retains 46.2% capacity after 300 cycles, outperforming standalone LR (4.9%) and LFP (12.8%). Characterization confirms that the LFP component suppresses structural degradation and voltage decay in LR, while the composite exhibits enhanced pseudocapacitive behavior and reduced charge transfer resistance (166.64 vs 252.23 Ω for LR). This work provides a simple yet effective strategy to synergize high capacity and structural stability, advancing practical applications of LR-based cathodes.

Monolithic photocatalysts present a transformative paradigm to reconcile the activity-stability-recovery trade-off inherent in conventional powder systems for photocatalytic hydrogen evolution. This study demonstrates a low-temperature synthesis of mesoporous Pt/Cu/TiO₂–N catalysts in situ grown on frosted glass (Pt/Cu/TiO₂–N/FP), where nitrogen doping amplifies Ti–O–Ti vibrational coupling and the hierarchical mesostructure creates sufficient active sites. The engineered Pt–Cu dual-cocatalyst system achieves exceptional synergy: Pt nanoparticles drive proton reduction while Cu²⁺ species prolong charge carrier lifetime through the Cu²⁺/Cu⁺ redox cycle, collectively enabling light absorption to the visible range. With optimized dual cocatalyst decoration (1.1 wt % Pt, 0.3 wt % Cu²⁺), the monolithic mesoporous architecture delivers a stable hydrogen evolution rate of 187.1 μmol h^–1. Importantly, our mild fabrication strategy (NH₃ treatment at 100 °C, Cu²⁺ grafting at 60 °C) establishes a generalizable protocol for temperature-sensitive substrate functionalization. This work pioneers a dual-engineering approach combining substrate-compatible synthesis with electronic structure modulation, offering a pathway toward industrially viable solar hydrogen reactors.

Rapid advancements in wearable electronics (WEs) have accelerated the development of textile-based triboelectric nanogenerators (T-TENGs) as flexible and sustainable power sources. However, one major challenge lies in mitigating the charge loss due to heat generation during repeated mechanical operations. In this work, we demonstrate a hybrid energy-harvesting textile that integrates both triboelectric and thermoelectric functionalities. Cotton (cot-) fabric serves as the triboelectric substrate, coated with a polyaniline/carbon nanotube (PANI/CNT) thermoelectric composite, enabling the simultaneous harvesting of mechanical and thermal energy. The optimized cot-PANI/CNT device exhibits a high Seebeck coefficient (98.5 mV/K), a power factor of ∼9 μW/mK², and improved electrical conductivity, while maintaining fabric flexibility. The hybrid system achieves an open-circuit voltage (V_OC) of ∼40.0 V and a short-circuit current (I_SC) of ∼77.3 μA, yielding a maximum output power of ∼272.3 μW (30.3 μW/cm²). The device successfully powers wearable-scale electronics, and mechanistic insights are provided into the synergistic charge generation pathways between the triboelectric and thermoelectric components.

Aqueous zinc ion batteries (AZIBs) are hindered from extensive application due to the sluggish kinetics of hydrated zinc ions and cathodic dissolution, which leads to the deficiency of cycling performance in zinc ion batteries. This work elucidates a series of sulfhydryl-rich binding agents (STN, SON, and SSN). The sulfhydryl groups suspended by the binders interact with the cations in the electrolyte, facilitating the transport of Zn²⁺, enhancing redox kinetics, and improving the cycling stability of the cell. Additionally, the formation of dynamic S–S bonds after the oxidation of sulfhydryl groups further restricts the volume expansion in the cathode during charge and discharge cycles, ensuring structural stability. The STN binder exhibits the most optimal performance. The N-containing triazine ring interacts with Zn²⁺, while the sulfhydryl group forms a dynamic coordination bond with Zn²⁺, thereby enhancing the Zn²⁺ storage and promoting the Zn²⁺ intercalation. This dual function ultimately produces a synergistic effect to optimize the electrochemical performance of AZIBs. The initial specific discharge capacity of the cell with the STN binder is 123 mA h g^–1 at 1 C multiplicity, which exceeds the 68 mA h g^–1 capacity of the cell with the PVDF binder.

Visible light-responsive photocatalysts enable enhanced solar energy utilization efficiency, offering a desirable way to address contemporary energy and environmental challenges. Emerging as a category of photoactive materials, conductive polymers [such as poly(diacetylenes) series] have demonstrated remarkable photocatalytic performance under visible light irradiation. However, the irregular morphology of conductive polymers forms more defect centers, which leads to a limitation of photocatalytic application. In this study, we successfully synthesized intrinsic two-dimensional (2D) poly(triacetylene benzene) (PTEB) nanosheets by an efficient template-free solvothermal method. The conjugated PTEB nanostructures possess an optimized narrow band gap energy (1.235 eV), demonstrating broad-spectrum absorption capabilities throughout both visible and near-infrared wavelengths. The 2D ultrathin structures of PTEB shorten the transport pathway of photoexcited charge carriers and facilitate their direct photocatalytic interaction on the surface. Benefiting from the 2D structures and narrow band gap, the as-synthesized PTEB exhibits superior photocatalytic performance compared to the P25 TiO₂ catalyst under ultraviolet and visible irradiation. It is proved that the degradation mechanism is mainly due to the action of reactive O₂^•– oxygen species. The visible-light-responsive characteristics exhibited by these organic semiconductors demonstrate significant potential for solar energy conversion and broader fields.

Niobium–based Wadsley–Roth oxides have recently attracted attention as promising anode materials for lithium-ion batteries, providing high charging and discharging rates and cycling stability. The higher operating potential of Wadsley–Roth oxide anodes, while impacting the overall energy density, reduces the risk of dendrite formation, making them safer at high power densities. We present the rapid preparation of two Wadsley–Roth oxide compounds, AlNb₁₁O₂₉ and Ti₂Nb₁₀O₂₉, by a microwave-assisted preparation method in under 10 min starting from oxide materials, and heating in open crucibles. No further processing is required to make effective electrode materials from these compounds other than grinding with the usual conducting carbon and binder. High-resolution synchrotron X-ray diffraction and scanning electron microscopy are employed to understand the impact of rapid preparation on the structure and morphology. Excellent electrochemical performance is achieved, with reversible capacities of up to 250 mAh g^–1 with high capacity retention over 100 cycles and fast-charging rates up to 10C without much loss of capacity. The materials reported here are compared to reports from the literature. Despite the very similar structures and compositions, AlNb₁₁O₂₉ is found to be less effective as an anode material than Ti₂Nb₁₀O₂₉, and in this work, we delve into possible reasons for this.

Solar energy emerges as one of the most promising sources for green electricity to tackle the issues caused by the continuous emission of greenhouse gases from the excessive use of fossil fuels. The intermittency of renewable, especially solar, energy-related challenges can be mitigated by integrating efficient energy storage technologies to complement the demand for off-sun hours. Supercapacitors (SCs) are promising energy storage devices due to their high power density and longer life spans, yet they rely on conventional electrical charging. Integrating photoactive materials in SCs may provide an additional degree of freedom to utilize solar energy simultaneously for charging; such devices are known as photorechargeable SCs (PRSCs). PRSCs enable both energy conversion and storage in a single device. PRSCs can provide consistent power to various applications ranging from smart, small portable devices to aerospace equipment. Hybrid-PRSCs can combine dual-functional electrodes (i.e., energy conversion and storage) and battery-type and carbon material-based electrodes. These hybrid-PRSCs are attracting much attention due to their higher specific capacitance and energy density. This review provides a detailed view of the recent advancement in PRSCs with different configurations, including four-electrode, three-electrode, and two-electrode systems based on the properties of materials for energy conversion and storage. The review also discusses the working mechanism of simultaneous energy conversion and storage processes for different PRSCs and characterization techniques with parameters to evaluate their performance. Two-electrode integrated PRSCs are preferred over other PRSCs and are discussed in detail, including the dual-functional materials and respective device parameters. This review emphasizes the current limitations and highlights the future perspectives of these PRSC devices as energy storage systems.

All solid-state sodium batteries (ASSSBs) are attracting significant research interest in an effort to decrease the raw materials competition and environmental damages caused by harvesting limited amounts of lithium, particularly for grid-scale energy storage applications. ASSSBs offer the advantages of being a more cost-effective and environmentally friendly solution to energy storage needs. To enable these ASSSBs, significant efforts have been made to develop new sodium solid-state electrolytes (SSEs). Glassy solid-sate electrolytes (GSEs) have been found to be particularly promising due to their high conductivities and processability. Here, the mixed oxy-sulfide (MOS) GSE, 0.59Na₂S + 0.30SiS₂ + 0.05PS_5/2 + 0.06NaPO₃ (NaPSiSO), has been found to exhibit excellent electrochemical performance at usable current densities while maintaining low interfacial impedances and high reductive and oxidative stabilities in contact with Na-metal (−0.5 V–3 V). At 80 °C, the NaPSiSO GSE exhibited an ionic conductivity of 4.8 × 10^–4 (Ω cm)⁻¹, a critical current density (CCD) of 0.85 mA cm^–2 and stable cycling at 0.1 mA h cm^–2 for over 900 h without shorting. Compared to its pure sulfide analogue, NaPSiS, the relatively small oxygen doped NaPSiSO, O/(O + S) ratio of 0.12, GSE shows significantly improved cycling performance and ionic conductivity. For these reasons, this new GSE is a promising candidate SSE for use in ASSSBs.

Na₃V₂(PO₄)₂F₃ (NVPF) is emerging as a promising positive electrode for sodium-ion batteries due to its high operating voltage. However, its inherent low electronic conductivity is the main obstacle to practical application. Although carbon incorporation could address this issue, it also accelerates fluorine loss during synthesis, forming impurities such as Na₃V₂(PO₄)₃ that compromise the high operating voltage of NVPF. Herein, the synthesis conditions are systematically investigated to obtain pure phase NVPF via a direct heating of the prepared precursor. According to the analytical results, the amounts of fluorine and carbon sources play an important role in the successful synthesis of pure phase NVPF, whereas the pH of the precursor solution has an unexpectedly limited impact on impurity suppression. The sample prepared in the optimal condition achieves excellent electrochemical performance, delivering 119.5 mAh g^–1 at 0.1C and remarkable long-term cycling stability. These findings provide insights into the scalable synthesis of high-purity NVPF for sodium-ion batteries.

The development of multivalent energy-storage systems is hindered by the scarcity of electrode materials capable of supporting the reversible intercalation of multivalent ions. Layered structures containing trigonal prismatic polyhedra offer a promising framework for efficient ion diffusion, leveraging the favorable coordination environments predicted by Pauling’s theory. Thus, this study is aimed at systematically examining the migration mechanisms of divalent ions (Ca and Mg) within NbS₂ and NbSe₂ layered structures, focusing on the influence of structural phases (2H and 3R) and coordination geometries (prismatic and octahedral). The migration behavior is modulated by coordination environments, ionic interactions, and local structural distortions, which collectively determine the energy barriers and diffusion pathways. Results demonstrate that trigonal prismatic coordination significantly reduces migration barriers compared with octahedral coordination, owing to the absence of coordination fluctuations during diffusion. Additionally, the choice of chalcogenide species affects migration barriers, with Se ions generally exhibiting lower migration barriers than those associated with S ions except in specific structural contexts. This work elucidates the intricate interplay among structural phases, coordination geometries, and chalcogenide composition, offering valuable insights into the design of advanced materials for multivalent ion storage.

Ni-rich single-crystal cathode materials have garnered significant attention for their ability to minimize intergranular cracking, enhancing cycling stability compared with polycrystalline counterparts. However, they remain susceptible to structural degradation, such as interlayer mixing, irreversible phase transformation, and intragranular cracking, which compromise the capacity during extended cycling. This study presents a strategy to address these defects by incorporating Mo through a two-step sintering process. Mo doping effectively suppresses the formation of oxygen vacancies, which is critical to the intragranular cracking formation, thereby improving structural stability and mechanical integrity. As a result, the doped cathodes demonstrate superior electrochemical performance, reduced impedance growth, and an enhanced cycle life. These findings offer valuable insights into the role of high-valence dopants in stabilizing single-crystal cathodes and contribute to developing high-performance lithium-ion batteries for next-generation applications.

While Na-based antiperovskites have emerged as a promising choice as solid-state electrolytes (SSEs) for sodium-ion batteries (SIBs), critical aspects regarding the influence of grain boundaries (GBs), mechanical stress, and their interaction on diffusion in these materials remain uninvestigated. We choose two model systems in cubic Na₃OCl (comprising Σ3(111) and Σ5(021) symmetric tilt GBs (STGBs)) and utilize molecular dynamics simulations to document the impact of GBs on Na-ion diffusion and the effects of mechanical stress on GB diffusion. Directional diffusion characteristics along and perpendicular to the GB plane are investigated in the unstressed state and under uniaxial, biaxial, and isotropic states of tensile and compressive loads. Our analysis reveals that Na-ion diffusion at Na₃OCl GBs is anisotropic and strongly influenced by the GB structure, with Σ3(111) STGBs potentially acting as fast diffusion channels and Σ5(021) STGBs severely inhibiting diffusion. Further, the effect of mechanical stress on GB diffusion is shown to be a complex function of GB type, stress state, and type of loading, with diffusion at Σ5(021) STGBs strongly influenced by stress while diffusion at Σ3(111) STGBs remains mostly unaffected. Given that fabrication conditions can substantially influence the types of GBs formed in polycrystalline samples, the demonstrated GB effects and stress–diffusion coupling call for careful tailoring of processing conditions for improving ionic conductivity of SSEs for SIBs.

Hybrid organic–inorganic perovskite solar cells (PSCs) present a leading thin-film photovoltaic technology with superior solar-to-electric power conversion efficiencies. The most effective compositions, however, contain lead cations, which are toxic and pose environmental hazards. One of the alternatives to lead-based perovskite materials is silver bismuth halide analogues. Here, we present a comprehensive investigation of different silver bismuth iodide compositions by means of density functional theory calculations (DFT) as well as X-ray diffraction, scanning and transmission electron microscopy, X-ray photoelectron spectroscopy, and photoluminescence spectroscopy measurements. Through our combined experimental and theoretical study, we have discovered that silver bismuth iodides possess several intrinsic limitations, such as limited charge transport and localized electronic states, owing to the presence of vacant sites. Such limitations result in moderate solar cell efficiencies, significantly lower than those of lead halide perovskites. However, we suggest the possibility of increasing efficiencies by adding BiCl₃ to the precursor solution, yielding one of the highest efficiencies reported for this class of compounds to date. This highlights the potential of compositional engineering for these lead-free solar cell materials.

The solvation structure of electrolytes plays a crucial role in determining the performance of sodium-ion batteries (SIBs). In this study, we employ a combined atomistic modeling approach of molecular dynamics (MD) simulations and density functional theory (DFT) calculations to investigate the impact of fluorination on the solvation structure and reductive stability of a series of fluorinated diethyl ether (FDEE) solvents for SIBs. Our findings reveal that fluorination significantly influences the Na⁺ solvation environment, leading to a decrease in solvation strength and a shift toward anion-dominated solvates. However, bilaterally substituted FDEEs with a low degree of fluorination exhibit enhanced solvation due to favorable Na–F interactions. Highly fluorinated FDEEs promote the formation of clustered solvation shells, reminiscent of high-concentration electrolytes, which facilitate Na⁺ desolvation and enhance reductive stability. Furthermore, we demonstrate that the position and degree of fluorination significantly affect the LUMO levels and reduction potentials of FDEE molecules, providing insights into their electrochemical stability. This study elucidates the complex interplay between fluorination, solvation structure, and electrochemical properties in FDEE-based electrolytes, offering valuable insights into molecular features that influence high-performance electrolyte design.

Employing water splitting (WS) to develop electrocatalysts for the hydrogen evolution reaction (HER) presents a promising strategy for generating cost-effective energy. In recent years, extensive research has focused on designing metal-based conjugated microporous polymers (CMPs) catalysts with abundant electrocatalytically active sites, offering an efficient substitute for precious metal-based Pt/C catalysts. In this study, a series of microporous pyrene-metal CMPs (Ru, Fe, Co, and Ni) were synthesized via a one-pot Schiff-base [4 + 2] condensation reaction between 4,4’,4’’,4’’’-(pyrene-1,3,6,8-tetrayltetrakis(ethyne-2,1-diyl))tetraaniline [PyBZ-TB-4NH₂] and [2,2’-bipyridine]-5,5′-dicarbaldehyde [BPy-2CHO] in the presence of different derivatives of transition metal salts (Ru, Fe, Co, Ni) to afford PyBZ-TB-BPy-M CMPs. The uncoordinated PyBZ-TB-BPy CMP and coordinated PyBZ-TB-BPy-M CMPs were investigated for their electrochemical HER performance. Notably, PyBZ-TB-BPy-Ru CMP exhibited an impressively minimal overpotential of 285 mV (at 10 mA cm^–2) and a charge transfer resistance (R_ct) of 245 Ω at 280 mV overpotential in 1 M KOH electrolyte. Furthermore, PyBZ-TB-BPy-Ru CMP demonstrated excellent stability, maintaining its electrocatalytic activity with minimal performance degradation after 18 h of chronoamperometry. Additionally, PyBZ-TB-BPy-Fe, PyBZ-TB-BPy-Co, and PyBZ-TB-BPy-Ni CMPs displayed enhanced electrocatalytic activity compared to the PyBZ-TB-BPy CMP. The exceptional performance of these metal-coordinated PyBZ-TB-BPy-M CMPs highlights their potential as cost-effective, low-resistance electrocatalysts with highly exposed active sites for efficient alkaline HER.

The PCE of inverted PSCs is increasing due to advancements in SAMs and passivation techniques. However, the imperfections in the buried interface and uneven deposition of perovskite films impede the operational stability and reproducibility of the PSCs. Herein, Y₂O₃–NPs were employed as a functional interlayer to improve the wettability of SAMs-based hole transport substrate, resulting in the perovskite films with higher crystallinity, fewer defects and desired homogeneity, thus promoting hole extraction and suppressing nonradiative recombination in the buried interface of PSCs. The photovoltaic efficiency of the resulting devices increases from 23.0% to 24.9%, which is accompanied by exceptional reproducibility.

This study presents an investigation into the properties of silicon/graphite anodes used in Li-ion batteries, focusing on the impact of ZnO coatings and the addition of fluoroethylene carbonate (FEC) to the electrolyte. We systematically compare the effects of ultrathin ZnO coatings on the silicon/graphite anode, prepared by using atomic layer deposition (ALD), with and without the FEC additive in the electrolyte. Both ZnO coatings and the FEC additive significantly influence the rate capability and long-term cycling stability of the anodes. The combination of ALD-deposited ZnO coatings with the FEC additive in the electrolyte exhibited the best performance, enhancing both the rate capability and capacity retention over extended cycling. These findings are further corroborated by electrochemical impedance spectroscopy (EIS), which highlights improvements in the anode performance. Additionally, post-mortem analysis using X-ray photoelectron spectroscopy (XPS) indicated an increased amount of LiF in the solid electrolyte interphase (SEI) layer. This increase in LiF content may contribute to the enhanced stability and performance observed in ZnO-coated anodes when combined with the FEC additive in the electrolyte.

Biomass-derived porous carbon offers an eco-friendly solution for energy storage, but challenges persist in optimizing the pore structure and electrochemical stability. In this study, we present a novel approach for fabricating nitrogen–oxygen-codoped porous carbon (NOPC) electrodes derived from sustainable longan shells, designed for electrical double-layer capacitors (EDLCs). The N₃OPC-3 electrode, optimized through high-temperature activation and surface doping with urea and nitric acid, exhibits outstanding electrochemical properties, achieving a specific capacitance of 463 F·g^–1 at a current density of 0.5 A·g^–1 in a 6 M KOH electrolyte during a three-electrode test. Furthermore, the symmetric supercapacitor based on N₃OPC-3 exhibits a high energy density of 31.9 W h·kg^–1 at a power density of 700 W·kg^–1, as well as an exceptional cycling stability, retaining 89% of its initial capacitance after 10,000 cycles. These superior performance characteristics can be attributed to the well-developed 3D hierarchical porous structure, which enhances ion diffusion, and the synergistic effects of nitrogen and oxygen doping, which promote pseudocapacitive behavior and improve electronic conductivity. The results highlight the potential of biomass-derived materials as sustainable, high-performance electrode materials for energy storage applications, offering an eco-friendly alternative to traditional carbon sources while addressing the growing need for efficient and scalable energy storage systems.

High-entropy materials have garnered significant attention as possible non-noble metal-based electrocatalysts for the production of hydrogen via water electrolysis. High-entropy oxides demonstrate high activity and stability at relatively low costs. This study presents the synthesis and characterization of NiCoCuFeMoMnO_x high-entropy oxide thin films deposited on graphite substrates via open-air pulsed laser deposition for electrocatalytic oxygen evolution reaction. The pulsed laser deposition process facilitates the oxidation of high-entropy alloy targets, forming a stable oxide phase. X-ray diffraction patterns reveal a mixture of amorphous (28.3%) and face-centered cubic crystalline (71.7%) phases. Morphological analysis using scanning electron microscopy and transmission electron microscopy shows a porous, flower-like structure, enhancing surface area and active site availability. Electrochemical measurements demonstrate significant improvements in oxygen evolution reaction performance with reduced overpotentials down to 180 ± 7 mV to reach 10 mA·cm^–2 and enhanced reaction kinetics. The high-entropy oxide films maintain stability over 100 h, showing improved catalytic efficiency after long-term stability measurements. Electrochemically active surface area and electrochemical impedance spectroscopy analyses indicate increased active surface area and reduced charge transfer resistance. These results highlight NiCoCuFeMoMnO_x high-entropy oxide films as promising robust electrocatalysts for efficient water splitting.

Green hydrogen production is a key factor in reaching climate goals. Proton exchange membrane water electrolysis (PEMWE) is one of the most promising technologies to achieve this, but it is limited by the poor electrocatalytic activity of the oxygen evolution reaction (OER), which requires high loadings of expensive and scarce precious metals, such as iridium. In this study, we synthesized iridium nanoparticles supported on titanium-oxynitride-decorated reduced graphene oxide (TiON/C). The prepared materials have been characterized using a variety of physicochemical methods, and the OER activity of iridium-based catalysts was assessed by cyclic voltammetry in acidic media. The plasma-assisted synthesis approach enables the preparation of electrocatalysts without the need for reducing agents, high-temperature annealing, or any other post-treatment. An outstanding mass-specific activity value of 11,700 A g^–1 reached at 1.6 V_RHE was obtained for the prepared Ir/TiON/C catalyst. The small Ir particle size and strong Ir–TiON interactions contribute significantly to the enhanced OER activity and good stability, demonstrating the potential of this material for efficient and sustainable hydrogen production with PEMWE.

As the widespread application of lithium-ion batteries and growing environmental protection requirements, it is of great research significance and commercial value to develop high-performance separator materials with both sustainability and economy. The aqueous polyacrylate dispersion (APD) is synthesized and applied to a cellulose-based membrane (CM) as an improved lithium-ion battery separator in this work. It is confirmed by structural characterization and morphological observation that APD is successfully coated onto the surface of CM to form a functional protective layer. The optimized CM-APD separator provides greater dimensional, thermal, and chemical stability, which is evidenced by lower dimensional shrinkage and less mass loss at high temperatures as well as a superior electrochemical stability window (5.29 V), in addition to excellent electrolyte uptake (154%) and ionic conductivity (2.31 mS·cm^–1). Besides, owing to enhanced electrochemical stability and interfacial compatibility by the functional groups in the APD, batteries with the CM-APD separator show significantly better operational stability and specific capacity compared to original CM and commercial polypropylene (PP) separators. Therefore, the improved cellulose separator CM-APD provides valuable insights for the development of high-performance lithium-ion batteries that satisfy both environmental friendliness and economic requirements.

This study explores an alternative hydrogen-pressure-mediated approach for electrochemical dehydrogenation and regeneration of lithium aluminum hydride (LiAlH₄). We systematically investigated the electrochemical oxidation/reduction behavior of 1 M LiAlH₄ in tetrahydrofuran (THF) under a 7 bar inert (Ar) and reactive (H₂) atmosphere. Under Ar, at electrode potentials >0.7 V vs Li, the oxidation reactions (alanate anions (AlH₄^–) → aluminum metal (Al⁰)) dominate. At reductive potentials, we observed an indirect role of deposited Li in forming a more porous Al surface and its interaction with LiAlH₄-THF that leads to adsorbed LiH/AlH₃ species, resulting in increased oxidation current density. Under H₂, the oxidation currents decrease due to the suppression of hydrogen-releasing reactions and the passivation of the Li surface by LiH formation. Further analysis of different working electrodes (Ni, Pd, and GC) revealed that Pd performs best under Ar and H₂ due to its inherent high catalytic activity. At the same time, Ni shows the best evidence for H₂ pressure-driven suppression of the AlH₄^– oxidation process. Electrochemical studies in Li-based electrolytes (LiBF₄ and LiTFSI) confirmed the formation of LiH under moderate conditions (room temperature, RT; 7 bar of H₂). Pulsed chronopotentiometry, ¹H NMR, and XRD analyses validated the presence of hydride species. Similarly, we observed a faster reactivity of dissolved H₂ with freshly deposited Al metal in an aluminum-containing ionic liquid (IL) electrolyte. However, ²⁷Al NMR studies suggested the formation of predominantly [AlCl₃(OH)]⁻ under H₂. Additionally, AlH₄^– was unstable in the presence of the IL with excess AlCl₃, highlighting the challenges of finding suitable electrolytes for stabilizing AlH₄^– species. This study provides fundamental insights into the feasibility of the electrochemical regeneration of LiAlH_4.

For energy storage, vanadium redox flow batteries (VRFBs) are very efficient, while stability and durability of membrane separator control battery performance. We synthesized sulfonated propyltrimethoxysilane graphene oxide (SPGO) as a nanofiller. Furthermore, the zwitterionic monomer [2-(methacryloyloxy)ethyl]dimethyl-(3-sulfopropyl)ammoniumhydroxide (DMAPS) was chemically grafted with partially fluorinated PVDF-co-HFP copolymer by free radical reaction with a 42.17% degree of grafting. Different zwitterionic membranes (P-DMAPS/SPGO) were prepared by incorporating SPGO as a nanofiller, and observed that the membrane with 3.0 wt % SPGO nanofiller (P-DMAPS/SPGO-3.0) exhibits superior VRFB performance. Incorporation of SPGO nanofillers significantly improved membrane stability due to the appropriate arrangement of functional groups responsible for hydrogen bonding. The suitably optimized P-DMAPS/SPGO-3.0 membrane exhibited excellent VRFB performance in a single cell with 98.23% Coulombic efficiency (CE) and 84.21% energy efficiency (EE) without any deterioration in the performance up to 350 cycles, which were significantly high in comparison with commercial Nafion-117 membrane (CE: 91.02%, EE: 70.84%). This was attributed to good ionic conductivity (9.89 × 10^–2 S cm^–1) and remarkably low vanadium ion permeability (5.33 × 10^–7 cm² min^–1) P-DMAPS/SPGO-3.0 zwitterionic membrane. Polarization curve of the P-DMAPS/SPGO-3.0 membrane also revealed a 442.8 mW/cm² peak power density at 540 mA/cm². In addition to VRFB, the synthesized ultrarobust and high-performance zwitterionic membranes may also find potential applications in diversified electrochemical applications.

Lithium manganese iron phosphate (LMFP) has attracted considerable interest for its superior energy density compared to LiFePO₄. Nonetheless, the practical implementation of LMFP faces challenges due to its naturally poor electrical conductivity and manganese dissolution, which arises from the Jahn–Teller effect. In this study, a comprehensive investigation of the synergistic effects of carbon coating was elucidated, demonstrating simultaneous enhancements in interfacial charge transport and structural stability. Experimental results highlight that precise control over the coating amount is a key strategy for achieving high-performance LMFP. The carbon serves as a physical barrier to avoid direct interaction between the LMFP and the electrolyte, mitigating the corrosion of Mn ions on the material surface caused by acidic components in the electrolyte. Further ex situ XRD analysis demonstrates that optimizing carbon content reduces lattice expansion during redox reactions, thereby improving the material’s structural integrity. Consequently, the optimized sample demonstrates enhanced electrical conductivity and a robust structural framework. It achieves an exceptional discharge capacity of 138 mAh/g at 2 C, along with outstanding capacity retention of 98.4% at 1 C after 300 cycles. This work deepens the research on carbon-coating modification and provides valuable insights into the design of olivine-based cathode materials with high Mn/Fe ratios.

Proton exchange membrane (PEM) water electrolysis cells can be operated very flexibly and at high current densities. Increasing the current density above today’s industrial standard, in combination with low loadings of the catalyst layer, is necessary to become more economical and resource-saving. The water consumption and gas evolution rate are proportional to the current density, leading to a significant difference in the volumetric water-to-gas ratio over the active cell area when operating at high current densities and low water flow rates. This study analyzes industrial-relevant PEM water electrolysis operation at high current densities of up to 7 A·cm^–², measured in a segmented along the channel test cell with a 30 cm channel length. We present locally resolved measurements of current density, temperature, and impedance spectra and discuss variations of operating parameters and porous transport layer microstructure for low-loading catalyst-coated membranes. To achieve a deeper understanding of the observed phenomena, we compare conventional voltage breakdown analysis, done by subtracting ohmic overpotentials through high-frequency resistance measurements, and kinetic overpotential using Tafel analysis with distribution of relaxation times (DRT) and equivalent circuit modeling. At industrially relevant operation with water stoichiometries greater than 50, no relevant mass transport losses or membrane drying effects are observed along the channel. In cases of low stoichiometries, combined with the high heat dissipation of the reaction at high current densities, a significant temperature increase of more than 8 K and a high-frequency resistance reduction along the channel are observed. Investigations using low-loading catalyst-coated membranes and different porous transport layers reveal a high sensitivity of local clamping pressure on the polarization processes but less impact on the high-frequency resistance.

The practical application of thermoelectric (TE) materials is often limited by the relatively underdeveloped performance of n-type materials compared to their p-type counterparts. Chalcopyrite CdSnAs₂ is a promising n-type semiconductor for thermoelectric applications owing to its narrow bandgap around 0.3 eV and exceptionally high electron mobility of 10³–10⁴ cm² V^–1 s^–1. In this study, we investigated the crystal growth, microstructure, and thermoelectric properties of CdSnAs₂. Contrary to conventional understanding of unidirectional melt growth, CdSnAs₂ samples grown at higher cooling rates exhibited better crystallinity, whereas some cracks were observed in those cooled more slowly. Thermal analyses revealed that a phase transition from sphalerite to chalcopyrite occurred after solidification in slowly cooled samples, resulting in the formation of dislocations and cracks due to lattice mismatch between the phases. In contrast, rapid cooling induced supercooling, which lowered the solidification temperature and enabled the phase transition to occur in the presence of a residual liquid phase, thereby leading to a more favorable microstructure. As a result, the sample grown at the highest cooling rate (7.6 K min^–1) achieved an ultrahigh power factor of 3180 μW m^–1 K^–2 at 600 K and a peak ZT of 0.59 at 682 K. The power factor of CdSnAs₂ surpasses that of conventional binary n-type TE materials such as SnSe and PbTe, underscoring its strong potential for intermediate-temperature thermoelectric applications.

The sulfide solid electrolyte Li₄SnS₄ exhibits significantly higher moisture stability against hydrolysis than other sulfide solid electrolytes and has attracted attention as a promising material for overcoming the inherent challenges of sulfide solid electrolytes. Li₄SnS₄ is known to exhibit two crystal phases: a hexagonal phase that is stable at low temperatures and an orthorhombic phase that forms upon thermal treatment at elevated temperatures. In this study, we investigated the effect of heat treatment at various temperatures on lithium ionic conductivity and found that, within a specific temperature range, the conductivity shows a distinct maximum, which coincides with the coexistence of hexagonal and orthorhombic phases. Synchrotron X-ray diffraction analysis revealed that nanosized orthorhombic crystallites are present within the overall hexagonal matrix near 250–300 °C, where the anomalous conductivity maximum appears. Further heat treatment at higher temperatures led to the growth of these orthorhombic crystallites, eventually resulting in a single-phase orthorhombic structure, during which the lithium ionic conductivity sharply decreased. We demonstrate that the characteristic nanoscale mixed-phase state (phase coexistence) serves as the key structural origin for the anomalous enhancement of lithium ionic conductivity in Li₄SnS₄, offering a specific insight into the design principles of heat-treatment protocols for sulfide solid electrolytes.

Metal–organic frameworks (MOFs) are attractive electrode materials for supercapacitors due to their high specific surface area, tunable pore structure, and excellent electrochemical properties. However, the factors that affect MOF morphology and performance still lack in-depth research. Herein, the impact of the mixture ligands of terephthalic acid (PTA) and 1,3,5-benzotricarboxylic acid (BTC) on the structure and electrochemical performances of MOFs was thoroughly explored. The micromorphology and crystalline structure of Ni-MOFs were modulated by adjusting the organic ligand ratio. And the optimized MOF structure facilitated electrolyte ion diffusion and then provided abundant redox active sites, which thereby significantly enhanced the electrochemical performance. In particular, Ni-MOFs with a molar ratio of PTA:BTC at 0.5:0.5 (NiMOF-0.5) exhibited superior electrochemical properties, with a specific capacity as high as 2009.12 F g^–1 at a current density of 1 A g^–1. Furthermore, an asymmetric supercapacitor (NiMOF-0.5//AC) was assembled with prepared NiMOF-0.5 as a cathode and biomass-based activated carbon as an anode, which exhibited a maximum energy density of 32.19 Wh kg^–1 at a current density of 1 A g^–1 with a power density of 970.49 W kg^–1. After 4000 cycles, it still kept a 95.23% of capacity retention. The results demonstrated that the dual-ligand strategy provided a promising approach for preparing MOF-based electrode material of supercapacitors.

The introduction of lithiophilic materials at the electrode surface represents a promising strategy for suppressing dendrite growth in lithium metal batteries (LMBs). Previous studies have demonstrated that the electrode morphology plays a pivotal role in achieving uniform lithium deposition, thereby enhancing overall battery performance. Lithiophilic seeds have been integrated into various electrode geometries, including porous, mesh, wire, foam, and nanopatterned structures. However, prior research predominantly focused on utilizing single-component lithiophilic materials to guide selective lithium deposition at the targeted sites. In this study, we report for the first time the development of heterostructures containing multiple lithiophilic elements on a line-patterned electrode. These heterostructures demonstrate the superior influence of contrasting lithiophilicity compared to conventional single-component lithiophilic seed designs on the performance of LMBs. Our findings indicate that introducing heterostructures with multiple lithiophilic elements in a guiding patterned electrode effectively controls lithium deposition behavior. Among the various configurations examined, a line-patterned electrode composed of a platinum (Pt) substrate with U-shaped gold (Au) wells (Pt/Au-well), providing modest contrasting lithiophilicity, exhibited the longest cycle life. In contrast, configurations such as Au/Cu, characterized by high contrasting lithiophilicity, or a single-component Au structure lacking contrasting lithiophilicity, resulted in nonuniform lithium deposition. Both half-cell and full-cell cycling tests revealed significant performance improvements, with the Pt/Au-well structure achieving over 200 cycles at a current density of 2 mA cm^–2 and a capacity of 2 mAh cm^–2, exceeding the cycle life of single-component lithiophilic structures by more than 2.5 times. These findings offer a promising pathway for the design and optimization of advanced LMB components, underscoring the critical role of tailored surface functionalities in improving the lithium deposition behavior.

Two-dimensional (2D) Janus MXene monolayers have emerged as promising candidates for photovoltaic and optoelectronic applications due to their highly tunable physicochemical properties, which enable optimized light absorption and enhanced power conversion efficiency (PCE). In this study, we investigate the structural, electronic, excitonic, and optical properties of 2D Janus MXenes with the general formula M₂CTT′ (M = Sc, Y; TT′ = FCl, FBr, ClBr) using density functional theory calculations combined with a semiempirical tight-binding approach. All six monolayers are found to be structurally stable, exhibiting a trigonal configuration with cohesive energies ranging from −5.74 eV/atom to −5.22 eV/atom. Their electronic band structures reveal an indirect semiconducting nature, with band gaps spanning 1.63 to 1.83 eV. The computed linear optical properties indicate strong absorption in the visible, infrared, and ultraviolet regions, reinforcing their potential for solar energy harvesting. Strong many-body effects are observed, with exciton binding energies between 249 and 373 meV, which are crucial for accurately describing energy conversion processes. The estimated PCE, evaluated using both the Shockley–Queisser (SQ) limit and the pectroscopy-limited maximum efficiency (SLME) approach, ranges from 25.5% to 32.6%, positioning these Janus M₂CTT′ MXenes as strong contenders for next-generation photovoltaic devices.

In this paper, gallium-doped indium oxide (In₂O₃) compounds with different doping amounts were fabricated through the hydrothermal method and the Spark Plasma Sintering process. X-ray diffraction showed that Ga was efficiently doped into the In₂O₃ lattice. The electrical conductivity is significantly improved by Ga doping, which is due to the reduced potential barrier of the carriers for the transition to the conduction band. The carrier concentration of Ga-doped In₂O₃ reaches 1.11 × 10²⁰ cm^–3, which is 12 times that of pristine In₂O₃, and the electrical conductivity (6.79 × 10⁴ S m^–1) is 5 times that of pristine In₂O₃. Furthermore, the lattice distortion in the doped sample acts as strong phonon scattering centers, which effectively reduce the mean free path of the phonons, resulting in a significant decrease in the lattice thermal conductivity. Finally, at 873 K, the zT value of In_1.88Ga_0.12O₃ reaches 0.22, which shows a 100% increase compared with that of the pure In₂O₃ sample. Our results show that the control of metal doping and microstructure can achieve synergistic optimization of the electrical properties and thermal conductivity of In₂O₃, providing a reference for other thermoelectric materials.

Coal gasification slag (CGS), which contains a significant amount of unburnt carbon residue, exhibits favorable conductivity and structural stability, making it a promising candidate as an anode material for sodium-ion batteries (SIBs). However, its high specific surface area and low degree of graphitization limit its sodium storage performance. To broaden the application of CGS, enhance the availability of carbon-based anode materials for SIBs, and reduce costs, this study proposes a synergistic strategy combining carbon nanofiber formation and presodiation to improve the sodium storage performance of coal gasification slag. After treatment, the residual carbon in the gasification slag achieves a discharge specific capacity of 247.07 mAh/g after 260 cycles at a current density of 0.05 A/g. To further enhance the initial Coulombic efficiency (ICE) and specific capacity of the electrode material, presodiation is employed. The modified material (RC-CNF-800-15) delivers a specific capacity of 345.34 mAh/g and an ICE of 35.78%. In summary, this study utilizes CGS as a raw material, employs a combined approach of fibrillation and presodiation, and modifies the sodium storage properties of the slag-derived carbon, thereby improving its electrochemical performance. This strategy not only opens avenues for the application of coal gasification slag but also expands the sources of anode materials for SIBs.

Electrochemical reduction of CO₂ to high-value chemicals is one of the most promising approaches to achieving sustainable carbon cycles. However, it is confronted by large challenges in designing active electrocatalysts that exhibit both high product selectivity and current density. Here, we report an atomic iron–indium dual-atom catalyst anchored on nitrogenated carbon (Fe–In-NC), which serves as a robust electrocatalyst for CO₂ reduction to CO. The Fe–In-NC catalyst demonstrates a superior CO Faradaic efficiency of 95% at −0.5 V vs RHE, surpassing that of the Fe-NC catalyst over a wide potential range from −0.7 V to −1.0 V vs RHE. Experiments and density functional theory calculations reveal that the d–p orbital electron coupling effect of Fe–In not only promotes the desorption of CO* but also reduces the barrier for the formation of COOH*. This work provides an effective strategy for tailoring the electronic structure of Fe single-atom catalysts, thereby enhancing their performance in energy conversion applications.

The local environment of an adsorption site is crucial in determining the adsorption energy. Understanding these local structural characteristics is thus key to optimizing adsorption properties, and this can be enhanced through machine learning (ML) models. In this study, we developed a compact set of five local descriptors (A, B, C, α, and β) that efficiently capture the structural features of the nearest neighbors (NNs) of around 18 different adsorption sites across six different borophene phases under varying external in-plane strain. Using an expanded data set of 131 data points and a fine-tuned ML model, we successfully mapped the descriptors to the hydrogen adsorption free energy (ΔG_H), achieving a low cross-validation MAE of 0.05 eV and a high R² of 0.95. Interpretation with SHapley Additive ExPlanations (SHAP) and radar charts revealed that the structure and coordination of the second nearest neighbors (B and β) play a dominant role in determining ΔG_H. Intermediate values of B and β are identified as optimal for HER, whereas extreme descriptor values lead to anomalous ΔG_H, which appear to be associated with outlier-like behavior in unrelaxed vacancy formation energy and adsorption charge density distortion cost. The insights from this study enhance the understanding of adsorption in borophene and demonstrate the effectiveness of compact local descriptors for adsorption studies.

Polyelemental nanoparticles (NPs) are an emerging class of nanomaterials that have been widely used in many fields including energy and catalysis. Establishing reliable synthetic methods that encompass a wide range of elements while allowing precise control of other particle parameters is crucial for the development of polyelemental NPs. In the past decade, synthesis methods for heterojunction, core–shell, solid solution, intermetallic, and amorphous polyelemental NPs have been extensively reported. Here, we summarize top-down and bottom-up synthetic strategies that overcome the challenges in balancing the different reduction potentials, atomic sizes, lattice structures, and miscibility of various elements to achieve delicate control of particle structure, size, and composition. As a unique characteristic of polyelemental NPs, the vast design space of catalytic sites can be used to systematically tune the adsorption of reaction species, which allows the creation of nanocatalysts with exceptional performance. In particular, we present some studies utilizing polyelemental NP catalysts for energy-related reactions, such as water splitting, fuel cell reactions, and carbon dioxide reduction reaction. The NP catalysts are categorized and discussed based on their elemental distribution differences, namely, disordered solid solutions, ordered intermetallics, and multiphase NPs. The mechanisms of catalytic enhancement on different types of polyelemental NPs are compared, providing insights into the design of efficient polyelemental nanocatalysts for the energy field.

Heusler alloys have attracted increasing attention due to their rich functionalities, among which Co₂MnSi, a half-metallic full-Heusler, is expected to be a promising n-type thermoelectric material with a superior power factor. However, the intrinsically high thermal conductivity of Heusler alloys due to their metallic nature limits the enhancement in thermoelectric performance. Therefore, it is crucial to reduce the thermal conductivity while maintaining the high power factor, which is a key strategy to fabricate high-performance Co₂MnSi alloys. Here, by incorporating a small amount of SiC nanoparticles into the Co₂MnSi matrix, the thermoelectric figure of merit is enhanced by approximately 5-fold from 0.03 to 0.15 at 1025 K, due to a significant reduction in thermal conductivity from 22 to 5 W/mK. The electrical transport properties do not suffer any obvious degradation after incorporation of a significant amount of SiC, while the mechanical strength of Co₂MnSi-based alloys is further improved. The thermoelectric device fabricated with Co₂MnSi as the thermoelectric legs is validated for solid-state refrigeration. It is also expected to promote the development of Co₂MnSi-based thermoelectrics with strong magnetism for new applications with multiple functionalities.

Electrochemical water splitting is a promising renewable energy generation method. Recently, the development of nonprecious water-splitting electrocatalysts has gained attention. However, it is challenging to discover nonprecious electrocatalysts that work well in hydrogen and oxygen evolution reactions. The hydrothermal hafnium nickel tungsten oxide production on nickel foam (HfNi-WO₃@NF) nanomaterials resulted in an efficient electrocatalyst. The synthesized electrocatalyst’s performance was excellent for the oxygen evolution reactions (OER) and the hydrogen evolution reactions (HER). The HER and OER require 106 and 246 mV overpotentials to 10 mA/cm² and 20 mA/cm² of current density. Likewise, in alkaline conditions (1 M KOH), the HER and OER need a decreased Tafel slope, 45 mV/dec for HER and 38 mV/dec for OER, to remain stable over an extended duration. A water-splitting electrolyzer using HfNi-WO₃@NF bifunctional nonprecious electrocatalyst generates a current density of 10 mA/cm² at 1.52 V and 1000 mA/cm² at 1.87 V. The same electrocatalysts have been used for seawater, requiring only 1.68 V with high durability under high current conditions for gravity-precipitated seawater samples. Nonprecious electrocatalysts are promising for hydrogen generation in abundant seawater electrolysis.

The development of platinum group metal (PGM)-free catalysts with high activity and stability for efficient reactants is a way to reduce the cost of fuel cell stacks and systems. However, the slow chemical reaction kinetics and poor stability of such catalysts remain significant challenges for their widespread application. Here, we report a high-performance Fe,Co–N–C/MnCo₂O₄/Ti₃C₂ + carbon nanotube (CNT) composite catalyst designed for the oxygen reduction reaction (ORR) in alkaline anion exchange membrane fuel cells (AEMFCs). The catalyst demonstrates exceptional ORR activity with a half-wave potential of 0.9145 V with only a 3.26% decrease after 10,000 cyclic voltammetry cycles. In AEMFC tests, the fuel cell performance based on the catalyst achieves a peak power density of 627 mW cm^–2 and 435 mW cm^–2 under H₂–O₂ and H₂–air, respectively. Furthermore, the catalyst exhibits remarkable durability with only a 20% decrease in power density after 200 h of continuous operation at 0.8 V. These results demonstrate that the catalyst is a promising material for fuel cell with high activity and stability.

Triboelectric nanogenerators (TENGs) have emerged as a promising energy-harvesting technology by converting mechanical energy into electrical power. However, enhancing their output performance remains a key challenge, primarily due to the limitations of triboelectric materials. In this study, polydimethylsiloxane (PDMS) is blended with bismuth sodium titanate (Bi₀.₅Na₀.₅TiO₃, BNT) to develop high-performance PDMS-BNT composites for TENG applications. Incorporating BNT enhances the dielectric constant of PDMS, leading to an enhanced charge-trapping capability and increased surface charge density. The composite film-based triboelectric nanogenerator operates in a single-electrode mode and demonstrates superior electrical performance. Specifically, the TENG achieves a voltage of 310 V and a current of 3.8 μA at a frequency of 1 Hz. The fabricated TENG generates a power output of 449 μW at a load resistance of 50 MΩ. Additionally, the TENG is capable of powering LEDs and calculator, highlighting its potential as a reliable energy source for low power electronics. Furthermore, the TENG was employed to capture energy from various human movements and used to monitor wind speed under both continuous and intermittent flow conditions, demonstrating its capability to harvest energy from low-frequency vibrations. This advancement paves the way for future applications in wearable electronics, environmental monitoring, and self-powered sensor networks, making it a promising technology for sustainable energy solutions.

The effective adsorption and conversion of sulfur species are essential to the performance of lithium–sulfur (Li–S) batteries. In this work, we designed a TMD-MXene-like material, Nb₂Se₂C, computationally by substituting the Nb layer of NbSe₂ with an Nb–C layer of Nb₂C. We investigated its catalytic activity toward lithium polysulfide (LiPS) adsorption and conversion, and compared it with NbSe₂ and Nb₂C using density functional theory (DFT) calculations. Adsorption energy analysis confirms that Nb₂Se₂C provides moderate and uniform binding across all LiPS species, ensuring stability and reversibility. In contrast, Nb₂C binds too strongly, impeding LiPS mobility, while NbSe₂ shows weak adsorption for smaller polysulfides. Notably, Nb₂Se₂C maintains moderate adsorption across LiPS species (S₈: −0.86 eV, Li₂S₆: −0.71 eV, Li₂S: −1.51 eV), preventing polysulfide accumulation. The Bader charge analysis further confirms its superior charge transfer ability, with negligible sulfur loss (S₈: −0.02|e| vs −1.33 |e|, for Nb₂C). Gibbs free energy (ΔG) profiles indicate Nb₂Se₂C promotes a relatively facile sulfur reduction step, with favorable steps from S₈ to Li₂S₈ (−2.55 eV) and minimal energy barriers, unlike Nb₂C, which exhibits high resistance (S₈ → Li₂S₈: +1.24 eV). Additionally, AIMD simulations conducted at 500 K confirm that all three materials are thermally stable. Overall, Nb₂Se₂C proves to be an excellent cathode host, efficiently suppressing the polysulfide shuttle effect, improving sulfur utilization, and optimizing Li–S battery performance.

PbS colloidal quantum dot (CQD)-based solar cells hold promise for solution-processed solar cells with wideband spectral sensitivity from the visible to the infrared region. In particular, an approximately one micrometer thick nanocomposite structure composed of the densely and intricately mixed infrared-absorbing PbS QDs and ZnO nanowires (NWs) effectively enhances the external quantum efficiency of photocurrent from the visible to the infrared spectrum because of the formation of spatially separate carrier pathways. This enlarged heterointerface makes the nanocomposite structure a promising candidate for a solar cell structure for high-efficiency infrared photovoltaics. However, since the recombination reaction mainly occurs at the heterojunction, improving open-circuit voltage (V_oc) is a critical challenge to fully capitalize on the performance of a nanocomposite with the enlarged heterojunction interface. To address this, we utilized the atomic layer deposition (ALD) technique to passivate the surface defects of ZnO NWs with Al₂O₃. A detailed analysis using high-resolution transmission electron microscopy (HR-TEM), scanning transmission electron microscopy (STEM), and energy-dispersive X-ray spectroscopy (EDS) confirmed that a precisely controlled ALD process enables the deposition of the conformal Al₂O₃ layer with the target thickness (3 nm) uniformly across the surfaces of ZnO NWs within the nanocomposite. Moreover, incorporating infrared-absorbing PbS quantum dots into the nanocomposite structure led to an increase in open-circuit voltage without compromising the short-circuit current density.

Layered double hydroxides (LDHs) synthesized via hydrothermal methods often suffer from restacking, leading to a reduced specific surface area and fewer active sites. Additionally, the use of binders in the electrode preparation process can introduce dead volumes, which, in turn, decrease the capacitance. To address this issue, we present the rational design of binder-free electrodes made of trimetallic zinc manganese cobalt-layered double hydroxide (ZnMnCo-LDH) nanosheets on nickel foam (NF) that are derived from metal–organic frameworks (MOFs). Cobalt-based MOF nanoflakes grow on NF, and ion exchange reactions produce the trimetallic ZnMnCo-LDH. The synthesis process of trimetallic ZnMnCo-LDH electrodes involves varying amounts of zinc and manganese precursors and synthesizes bimetallic layered double hydroxides (LDHs) using similar experimental conditions for performance comparison. At the optimized conditions, the ZnMnCo-LDH electrode exhibits the highest specific capacitance (C_F) of 1508 F/g at 20 mV/s. Furthermore, we fabricate an asymmetric supercapacitor (ASC) with a ZnMnCo-LDH positive electrode and an Ultraphene negative electrode. This ASC provides excellent energy storage performance with an appreciable energy density of 40.1 Wh/kg and a power density of 700 W/kg. Also, superior cycling stability with a C_F retention of 95% and a Coulombic efficiency of 94% is achieved after 10,000 charge/discharge cycles.

Cyclized polyacrylonitrile (cPAN) synthesis entails a multistep process encompassing cyclization, the elimination of NH₃, H₂, and hydrogen cyanate (HCN) gases, and graphitization. This process yields a semiconducting polymer that, when paired with sulfur, is used as cathode materials in Li–S batteries or, under elevated temperatures, produces carbon fibers. Within this framework, we comprehensively characterized cPAN obtained through varying temperature regimes. Utilizing scanning electron microscopy (SEM) and transmission electron microscopy (TEM), alongside infrared and Raman spectroscopies, we scrutinized the samples subjected to thermal treatment. Together, employing density functional theory (DFT), we investigated the potential reaction pathways implicated in the heat treatment of cPAN, while also investigating its viability as a cathode material through DFT calculations and electrochemical characterization using a pontetiostat. Our inquiry emphasizes pivotal insights concerning the structural nuances of cPAN, with a critical state of the structure commonly proposed in the literature. Finally, we assembled and characterized the cPAN as an active material for lithium batteries in a range between 0.2 and 4.6 V, inducing, at high voltage, overpotential reactions that modify the capacity of the cPAN. Thus, cPAN can be considered a material that can be used as anode and cathode material in lithium batteries, according to the electrochemical conditions.

Energy harvesting using galvanic cells in the gastrointestinal (GI) tract can provide supplementary power and prolong the service life of ingestible devices. This paper explores the impact of electrode type, dimension, and varying gastrointestinal (GI) conditions on the performance of galvanic cells for powering ingestible devices. In vitro experiments were conducted with varying cathode and anode combinations in synthetic gastric fluid (SGF) under a load resistance sweep to measure the voltage of the galvanic cell. Eighteen tests assessed the peak power, energy capacity, and longevity of each electrode pair. Galvanic cell performance was also evaluated under simulated GI conditions, including varying pH, salt concentration, added foreign substances, and simulated intestinal conditions. Pt and Pd cathodes showed the highest peak power and energy capacity, while Mo was cost-effective for transient applications. Mg was optimal for short-term use, while Zn or the AZ31B Mg alloy were preferred for long-term applications. Energy generation decreased with increasing pH but improved with higher salt concentration. Large substances in gastric fluid hindered performance, and energy generation in intestinal fluids was less efficient. Larger cathode-to-anode size ratios increased efficiency, while larger anodes provided greater longevity. This study successfully characterized the effects of electrode combinations, GI conditions, and dimensions on the performance of galvanic cells, offering insight into the design of supplementary power sources for ingestible devices. These findings aid the development of galvanic cells for short-term and long-term applications in ingestible devices.

Currently, hard carbon (HC) is the most promising negative electrode material for sodium-ion batteries due to its low redox potential, high-rate performance, and good reversible capacity. However, the synthesis procedure and choice of precursors are known to strongly impact the resulting HC performance. Herein, we focus on lignin as an abundant, high-yield precursor for the synthesis of HC. Using a three-step procedure involving preheating, washing, and postheating steps, we observed major improvement in the performance (ca. 340 mAh g^–1) and with high HC yields of ∼40%. We found that the preheating temperature (200–800 °C) impacted the reversible capacities and the plateau potential during sodiation, located around ∼40–70 mV vs Na⁺/Na. Based on small-angle X-ray scattering, we could correlate the size and content of the micropores with the observed plateau potential. The washing step was found to be key to removing impurities within the lignin structure, which tended to activate the carbon and reduce the reversible capacity. For the postheating step, HCs prepared using 1200–1300 °C showed the highest performance. Overall, lignin is a very promising, cost-effective precursor for preparing HC, and by optimizing its synthesis, major improvements to the negative electrode performance can be realized, which may also be relevant for HC synthesis from other precursors.

Lithium–sulfur (Li–S) batteries are one of the most promising next-generation energy-storage systems due to their high energy density (2600 Wh kg^–1). Nevertheless, the shuttle effect caused by the dissolution of lithium polysulfide (LiPS) interrupts the commercial application of Li–S batteries. Graphitic carbon nitride (GCN), with an enriched density of pyridinic-N sites for LiPS adsorption, has been explored as an effective adsorption material to inhibit the migration of polysulfides. However, the inferior conductivity of GCN imposes limitations on sulfur utilization in Li–S batteries. Herein, the boron-doped, nitrogen-defect GCN (BCN4_–x) is designed as a slurry additive to synergistically enhance the adsorption strength of LiPS and the conductivity of GCN. Boron doping in GCN enhances positive polarization, improving the conductivity of GCN. Additionally, B-doping induces nitrogen defects and cyano groups, increasing the polarity of the GCN. Based on UV–Vis absorbance, BCN4_–x exhibits a stronger affinity for LiPS compared to GCN. Moreover, compared to pristine GCN, BCN4_–x achieved 20% higher capacity retention (71.33% after 100 cycles at 0.5 C) and 1.7 times greater rate performance (803.01 mAh g^–1 at 1.0 C) in Li–S batteries due to a synergistic effect.

The glucose oxidation reaction (GOR) is emerging as an energy-efficient alternative to the oxygen evolution reaction (OER), owing to its lower thermodynamic potential and the simultaneous production of value-added chemicals from biomass feedstocks. In this work, we report a bifunctional Fe_xCo_2-XP/NF electrocatalyst, integrated onto a nickel foam (NF) substrate, synthesized via a controlled metal–organic framework (MOF)-derived phosphorization strategy. The resulting Fe_xCo_2-XP/NF electrode demonstrates outstanding electrocatalytic activity toward both the GOR and overall water splitting, achieving low overpotentials of 205 mV and 119 mV for the OER and hydrogen evolution reaction (HER), respectively, at 10 mA·cm^–2. The Fe_xCo_2-XP/NF (±) electrode demonstrated a low cell voltage of 1.44 V for the GOR/HER system at a current density of 10 mA·cm^–2, which is substantially lower than the 1.72 V required for the conventional OER/HER configuration. This reduction in energy input, combined with the production of valuable chemicals, highlights the dual functional advantage of the GOR. The improved catalytic performance is attributed to the synergetic integration of FeCo alloy nanostructure with N-doped carbon within a porous 3D framework, enhancing charge transfer, stability, and active site accessibility. These findings present a scalable and innovative approach for simultaneous green hydrogen production and biomass valorization, aligning with the goals of sustainable and economically viable energy systems.

Antimony sulfide (Sb₂S₃) is an emerging wide bandgap semiconductor material with outstanding optoelectronic properties and potential applications for cost-effective and low-toxicity solar cells. Here, we report on the fabrication of Sb₂S₃ thin-film solar cells via a hydrothermal approach followed by postannealing and light soaking treatments. We investigate the process optimization of hydrothermal deposition, postannealing, and light soaking conditions. The results show that the hydrothermal growth at 135 °C for 225 min, combined with 350 °C postannealing for 10 min, leads to a champion power conversion efficiency (PCE) of 6.89%. Furthermore, light soaking of completed devices under one-sun irradiance at 70 °C for 120 min enhances the PCE to 7.69%. The device analysis implies that the performance improvement is mainly attributed to the enhanced charge transport properties in the hole transport layer. Our findings demonstrate a facile procedure to improve the photovoltaic performance of Sb₂S₃ solar cells.

Developing a stable, solar-absorbing layer with earth-abundant elements is key for next-gen photovoltaics. A Mott insulator (MI) transition metal oxide like LaMnO₃ (LMO) offers affordability and stability, making it promising for solar cells. This study explores a comprehensive experimental and theoretical investigation into its photovoltaic efficiency using the pulse laser deposition (PLD) technique and SCAPS-1D simulation tool. We employed the Nb: SrTiO₃ (NSTO) substrate and Cu₂O as the electron transport and hole transport layers, respectively. A detailed structural characterization via X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), and Raman spectroscopy studies confirms the highly crystalline c-axis oriented growth of the LMO perovskite phase. Characterization of the optical properties via diffuse reflectance spectroscopy (DRS) identifies a direct band gap of 1.15 eV for LMO, while the photoluminescence (PL) measurements reveal an emission peak at 460 nm, indicating no relaxation processes. The first-principle calculations suggest that the system possesses similar electronic and optical band gaps, which closely align with the experimental results observed in the Tauc plot. Additionally, we have conducted a simulation study of the solar cell with a planner architecture as Nb:STO/LMO/Cu₂O and compared it with the experimental results from a PLD-grown LMO solar cell. The simulation results predict a power conversion efficiency (PCE) of 6.2%, while the experimentally grown solar cell achieves a PCE of 0.9%, which may be due to the limited charge transport kinetics. More importantly, inserting a correlated metallic SrRuO₃ (SRO) buffer layer in the device offers a significant enhancement of the PCE (∼38%) from 0.9 to 1.25%, highlighting better electron transport (J_sc increased by 118%). Impedance measurements on the optimized Nb:STO/SRO/LMO/Cu₂O/Au device revealed a series resistance of 52.6 Ω and junction capacitance of 96.8 pF. Our complementary experimental and theoretical findings on these solar cells signify a pivotal advancement toward realizing MI solar cells beyond conventional semiconductors.

Solution processing of perovskite materials presents a scalable approach for high-throughput, roll-to-roll fabrication of lightweight and cost-effective flexible solar cells (f-PSCs). The final cost of f-PSCs is significantly influenced by material costs, fabrication speed, and energy consumption during material processing. Notably, the use of expensive organic charge transport layers, such as electron transport layers (ETLs) and hole transport layers (HTLs), substantially increases production costs. Moreover, conventional conductive and convective annealing methods are time-intensive, energy-consuming, and impractical for high-speed continuous manufacturing, further driving up fabrication costs. In this study, we demonstrate intense pulsed light (IPL) as a rapid, millisecond annealing method for f-PSCs on PET substrates, employing low-temperature-processable nickel oxide (NiO_x) and tin(IV) oxide (SnO₂) as cost-effective HTL and ETL materials. Flexible perovskite solar cells were fabricated via blade coating with IPL serving as the sole annealing step. By modifying room-temperature-deposited NiO_x with Me-4PACz, we achieved a power conversion efficiency (PCE) exceeding 17% for mixed cation perovskite composition (FA_0.86MA_0.14Pb(I_0.95Br_0.05)₃) on ITO-PET substrates, using metal oxide charge transport layers and IPL annealing exclusively.

The limited application of rechargeable zinc–air batteries (ZAB) is mainly attributed to the sluggish kinetics of the oxygen reduction reaction (ORR) in an air cathode. Therefore, designing catalysts to improve the ORR kinetics is significantly important. Herein, we synthesize metal oxide-decorated ZnS nanoparticles (NPs) supported on nitrogen-doped porous carbon (denoted as M_xO_y-ZnS-N-C; M = Fe, Co) by a two-step pyrolysis strategy. The lattice contraction of ZnS NPs induced by the introduction of the M_xO_y moiety is confirmed by systematic characterizations, including XRD, TEM, and XANES. The Fe_xO_y-ZnS-NC/Co_xO_y-ZnS-NC catalysts exhibit an apparently improved ORR activity with E_1/2 of 0.895/0.86 V, respectively, compared to the pure ZnS-N-C reference sample (0.75 V). Importantly, the Fe_xO_y-ZnS-NC ORR catalyst-based ZAB also delivered a high power density of 243 mW cm^–2 and a long durability over 400 h. These excellent properties of M_xO_y-ZnS-NC catalysts were attributed to the fact that introduction of M_xO_y leads to the lattice contraction of ZnS NPs, which efficiently optimizes the electronic structure of the as-prepared samples and therefore improves the ORR performance. This paper provides a useful strategy of using lattice strain to regulate the electronic structure of catalysts for boosting their electrochemical properties.

The present work investigates the growth, microstructure, and phase evolution of reactively sputtered Ta–N thin films deposited on Al₂O₃(0001) substrates with and without a Ta₂O₅ seed layer using complementary experimental techniques and theoretical calculations. X-ray diffraction (XRD) patterns reveal that without a seed layer, the films predominantly consist of the (111)-oriented cubic δ-TaN phase. In contrast, Ta₂O₅ seed layers promote the formation of an orthorhombic Ta₃N₅ phase with preferred orientation along the c-axis. Scanning transmission electron microscopy (STEM) results show the presence of large epitaxial Ta₃N₅ domains. Thickness-dependent XRD patterns and STEM images, together with fast Fourier transform studies, reveal that the transformations from β-Ta₂O₅ to a Ta–N mixed phase and finally to Ta₃N₅ take place during film growth. This observed phase transformation depicts that the seed layer serves not only as a structural template for the epitaxial growth of Ta₃N₅ but also as an active participant in the nitridation process during growth. Energy calculations suggest that the Ta–N species play a crucial role in stabilizing Ta₃N₅ growth. This work elucidates the complex interplay among seed layers, deposition conditions, and precursor energetics, offering a comprehensive understanding of Ta₃N₅ thin film epitaxial growth mechanisms.

Biomass hard carbon is commonly used as an anode material for sodium-ion batteries (SIBs); however, the lower cycling stability and capacity retention limit its large-scale application. In this study, polyaniline-modified spherical sisal fiber carbon (PAN@SSFC) was prepared by a surface coating method using sisal fiber as a precursor. And the effects of morphological conditions on cycling stability and capacity retention were also explored. The prepared PAN@SSFC composites have unique nanostructured protrusions, large crystal plane spacing, and moderate specific surface area, which facilitates the rapid transfer of sodium ions and large ion adsorption. Compared to SSFC, the PAN@SSFC shows a much better electrochemical performance with a reversible specific capacity up to 239 mAh g^–1 after 1000 long-term cycles at a current density of 0.1 A g^–1 and 77.4% high capacity retention. Through analysis of the capacity changes in the discharge curves, it can be explained that the sodium storage behavior of PAN@SSFC follows an “adsorption–insertion/filling” mechanism. This study paves the way to develop anode materials for sodium-ion batteries with outstanding cycling stability.

In this work, nickel nanoparticles were prepared on the surface of the TiFe_0.8Mn_0.15Zr_0.05 alloy by electroless deposition. The effects of nickel nanoparticles on hydrogen storage properties and oxidation resistance of the TiFe_0.8Mn_0.15Zr_0.05 alloy were systematically investigated. The results showed that the amount and distribution areas of nickel nanoparticles enlarged with the deposition time (0, 10, 15, 20, 30, and 40 min). With the continuous accumulation of nickel nanoparticles, the maximum hydrogen storage capacity decreased slightly from 1.89 wt % (0 min) to 1.80 wt % (40 min). In addition, the hydrogenation reaction rate of all samples presented a trend of increasing first and then decreasing with deposition time. The pristine alloy required approximately 1372 s to achieve 90% capacity during the first hydrogenation. In contrast, the nickel nanoparticle-coated alloys with deposition times of 10 and 20 min demonstrated significantly faster kinetics, requiring only 63.05% and 77.99% of this time, respectively. The phenomenon revealed that nickel nanoparticles enhanced hydrogenation kinetics and the catalytic activity of nickel nanoparticles to hydrogenation kinetics was closely related to distribution and arrangement. At the same time, the deposition of nickel nanoparticles barely changed the thermodynamic properties of the alloy. The enthalpies of hydrogen absorption of pristine alloy (0 min) and nickel nanoparticle-coated alloy (40 min) were −24.817 and −23.478 kJ·mol^–1, respectively. More importantly, the oxidation resistance of alloy had a significant improvement after being modified by nickel nanoparticles. Finally, the rate-limiting step of the first hydrogenation of all samples before and after air exposure was studied in detail.

Actinide-bearing molten salts for use as fuels are an essential part of next generation molten salt reactors. Yet, numerous multicomponent salt mixtures are underdeveloped or have not been investigated. This study, based on a combination of experimental and modeling techniques, is dedicated to determining and understanding a variety of properties of the ternary system of NaCl–UCl₃–PuCl₃, which represents a scenario for burnup of NaCl–UCl₃ fuel, at two compositions (∼10 and 5 mol % PuCl₃ in eutectic NaCl–UCl₃ pseudobinary) and a range of temperatures. Evaluation of the heat flow and mass loss data showed the 0.61NaCl–0.30UCl₃–0.09PuCl₃ salt had a melting temperature of 551 ± 5 °C. Two additional thermal effects were observed occurring at approximately 410 and 494 °C. The transition occurring at 410 °C may be due to the presence of oxide in the salt. Extrapolation of thermodynamic data indicates the transition occurring at 494 °C is due to the formation of a liquid phase. Experimental testing determined the density of this system is a linear function of temperature and can be represented by the equation ρ = 4.014–0.0010T(°C), R² = 0.992. Additionally, by using atomistic modeling, we found that increasing the PuCl₃ content from 5 to 10 mol % led to the formation of larger Pu³⁺ clusters and slower transport of ions.

The advancement of miniaturized, high-efficiency nanogenerators for energy harvesting demands precise characterization of piezoelectric and triboelectric outputs. This study employs a unique methodology to isolate and characterize the piezoelectric and triboelectric signals from the as-received piezoelectric output, enabling an accurate evaluation of the true piezoelectric response. Ground shielding layers were employed to suppress triboelectric interference, contributing toward precise evaluation and optimization of the actual piezoelectric output. A detailed investigation of the signal generation mechanisms based on dynamic electric field formation was conducted, revealing distinct charge redistribution behaviors governing piezoelectric and triboelectric contributions. The triboelectric signal exhibited its typical characteristics, including a longer response time and a smoother curve than that of the piezoelectric signal. Additionally, nanocapacitor-based mechanisms owing to nanoparticle inclusion were explored to enhance charge storage and polarization effects within the system, leading to improved energy conversion efficiency. These insights were leveraged to develop an integrated hybrid piezo/tribo nanogenerator (PTNG), where triboelectric interference was strategically utilized as a functional amplification mechanism. The final optimized PTNG exhibited a peak-to-peak output voltage of 81.58 V, a current density of ∼6.4 μA/cm², and a power density of ∼240 μW/cm², demonstrating its potential for efficient energy harvesting in portable electronics. These findings establish a robust framework for precise piezoelectric performance evaluation while highlighting the potential of compact and integrated hybrid devices for achieving device miniaturization without sacrificing efficiency. This work paves the way for sustainable energy solutions in flexible electronics and wearable sensor applications.

Despite significant advancements in heterostructure catalysts to alleviate polysulfide shuttling for lithium–sulfur (Li–S) batteries, the importance of synergistic interactions among multiple materials remains overlooked. Herein, we report the rationally designed TiO₂@V₂O₅@CdS heterostructures that take advantage of complementary structural and electronic properties to reinforce the adsorption to lithium polysulfides (LiPSs) and accelerate the sulfur redox kinetics. The modulation of the TiO₂ nanoarray and V₂O₅ shell offers a steady interface and moderate adsorption to LiPSs, facilitating rapid aggregation of intermediates. Meanwhile, the optimized electronic structure achieved by the modification of CdS quantum dots enhances catalytic activity for bidirectional LiPSs conversion. Benefiting from the synergy of adsorptive modulated oxides and catalytic CdS, TiO₂@V₂O₅@CdS heterostructures establish an efficient and sustainable adsorption-conversion of LiPSs with accelerated ion diffusion and reduced reaction energy barrier. Consequently, Li–S batteries with a TiO₂@V₂O₅@CdS cathode exhibit excellent cycling stability over 1000 cycles with a degradation rate of 0.0413% per cycle at 1 C and an impressive areal capacity of 4.56 mA h cm^–2 under a high sulfur loading of 4.5 mg cm^–2. This work presents a complementary design of heterostructures that leverage structural and electronic synergies to improve the performance of Li–S batteries.

Two-dimensional (2D) MPX₃ (X = S, Se) materials possess an abundance of catalytically active sites, making them promising candidates for efficient catalysis. In this study, NiPS₃-loaded ZnIn₂S₄ (NPS/ZIS) heterostructures were synthesized. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) confirmed the formation of a tightly integrated heterojunction between NPS and ZIS. Diffuse reflectance spectroscopy (DRS) and X-ray photoelectron spectroscopy (XPS) observations indicate that ZIS and NPS form a type I heterojunction. Furthermore, density functional theory (DFT) calculations reveal the presence of a built-in electric field from ZIS to NPS, facilitating effective electron transfer. Meanwhile, NPS functions as an efficient reductive cocatalyst, lowering the energy barrier for hydrogen evolution and thereby enhancing reaction efficiency. Photocatalytic experiments revealed that the introduction of NPS significantly promotes the photocatalytic hydrogen evolution under visible light irradiation (>420 nm). Specifically, the photocatalytic hydrogen evolution rate of the 2-NPS/ZIS heterostructure (containing 5.0 wt % NPS) reaches 7.8 mmol·g^–1·h^–1, which is 7.0 times higher than that of pristine ZIS and significantly exceeds the activity of traditional noble-metal cocatalyst Pt-loaded ZIS. Cycling tests showed that 2-NPS/ZIS remained stable during photocatalytic hydrogen evolution reaction (HER), with no significant decay in HER activity over an 18 h reaction period. This study provides valuable insights and approaches for the development of low-cost, high-efficiency photocatalysts for photocatalytic hydrogen production.

Solid propellants are the primary sources of propulsion energy for rockets. Their energy characteristics determine the payload capacity and range of rockets. To design higher-performance solid propellants, it is often necessary to perform a high-precision quantification of the enthalpy of formation (EOF) for the component materials before conducting thermodynamic calculations. However, this process is inefficient and time-consuming. Herein, a machine learning (ML) framework integrating ML with genetic algorithms (GAs) was introduced to accelerate the design of solid propellants, allowing for accurate and rapid prediction of energy characteristics of propellants, only with the mass ratio and chemical formulation of each component as input. Leveraging the proposed framework, three propellant formulations with the ratios very close to the best-reported ratios were identified by using GAs, thereby validating the reliability of this framework for designing solid propellants. By applying high-throughput screening within this framework, seven promising energetic compounds (ECs) were identified from over 1000 candidates, with the potential to increase the specific impulse (I_sp) to 278 s and to enhance the rocket range by up to 45%. This study highlights the practical application of ML in predicting energy characteristics of solid propellants and establishes methodologies for advancing their intelligent design.

As Moore’s Law approaches its physical limits, the traditional von Neumann architecture faces challenges, and memristors offer hope as a new type of device structure. In this study, we realized the ultralow energy consumption (1.1 fJ) artificial synapse based on 2D InSe with small effective electron mass and high electron mobility. Furthermore, we simulated the synaptic behaviors of post-tetanic potentiation, classical conditioning, spike-rate-dependent plasticity (SRDP), and Bienenstock–Cooper–Munro (BCM) learning rule. This study not only provides a simulation of synaptic behavior but also achieves edge recognition in images through an effective adjustability.

[PTiW₁₁O₄₀]^5–, a Ti = O derivative of [PW₁₁O₃₉]^7– lacunary Keggin polyoxometalates (POMs), is employed as an excited state electron reservoir for the hydrogen evolution reaction (HER) via water-splitting in the presence of sacrificial agents. This POM also stabilizes the surface of crystalline anatase TiO₂ NPs to provide a well-dispersed TiO₂-[PTiW₁₁O₄₀]^5– hybrid material. Modifications of the bandgap through self-doping on the anatase surfaces, along with impregnation of ultrasmall Ni NPs, were executed, resulting in self-doped TiO₂-[PTiW₁₁O₄₀]^5–-Ni ternary hybrid materials with improved absorbance in the visible regions. Various analytical techniques, such as Tauc plots, powder XRD, HAADF-STEM, and XPS, were used to characterize these synthesized ternary hybrid materials. These hybrid materials showed very high photocatalytic activity under UV–vis and visible-light irradiation. These hybrids also display a very low Tafel slope of 62 mV dec^–1 toward electrocatalytic HER activity. A comprehensive mechanistic investigation elucidating the electron transfer dynamics during hydrogen evolution is shown here. Under photo- and electrocatalytic conditions, Ni NPs act as active sites for hydrogen evolution, whereas POMs act as excited-state electron scavengers and storage. According to a molecular-level calculation, the ternary hybrid’s Ni NPs active-site-dependent HER effectiveness exhibits a “dose-response” relationship in comparable experimental conditions. The Hill slope coefficient highlights the cooperative mechanisms between the Ni active sites for H₂ production during catalytic turnover.

A platinum-containing hexaaminotriphenylene (HATP, 2,3,6,7,10,11-hexaaminotriphenylene, [C₁₈H₁₂N₆]) hybrid cocrystal material ([Pt(acac)₂][HATP]) has been synthesized and used as a precursor that was pyrolyzed to produce an oxygen reduction reaction (ORR)-active electrocatalyst. The crystalline precursor, pyrolyzed in vacuo and monitored in situ with temperature-variable TEM, was found to form an amorphous carbon network intercalated with crystalline platinum nanoparticles (NPs). The thermal decomposition of the coordinated hexaaminotriphenylene ligand, with loss of the amino groups around 300 °C, is concomitant with the reduction of platinum centers from Pt²⁺ to Pt⁰, while the pyrolysis time and temperature control the ultimate size of the nanoparticles. Pt nanoparticle growth above 300 °C was found to be limited, likely as a result of the nanoparticles being trapped in a carbon network that formed from the HATP molecules during the pyrolytic process. Samples of the pyrolyzed material were investigated by RDE for ORR catalysis in an acidic medium and were found to have a modest electrochemical surface area (38.8 m²/g_Pt) and a mass-specific activity of 58.5 mA/cm_Pt².

Rechargeable lithium-oxygen (Li-O₂) batteries are at the forefront of energy storage technology. Yet, they face critical challenges, including poor capacity, high overpotential at the oxygen cathode, inefficient lithium utilization, oxygen crossover, and the troublesome growth of lithium dendrites. This study provides an innovative solution using a graphene nanosheet (GNS) composite nickel ferrite (NiFe₂O₄) (NiFe₂O₄@GNS) catalyst and ZIF-8 particles decorated glass fiber (GF) (ZIF-8@GF) separator. Remarkably, the in situ grown ZIF-8@GF composite separator boosts higher ionic conductivity (∼2.87 × 10^–3 S cm^–1) and transport number (t_Li+ ∼ 0.58). The modified catalyst and separator performed significantly better than the unmodified analogs in terms of specific capacity and cycling stability. In short, the device using the ZIF-8@GF separator and NiFe₂O₄@GNS catalyst goes up to 500 cycles without any charge polarization at 300 mA·g^–1 and 500 mAh·g^–1. In contrast, the corresponding cycle number for the cell with an unmodified separator even using the modified catalyst is ∼209 cycles with high charge polarization. These studies reveal that the modified separator effectively minimizes oxygen and I^–/I₃^– redox crossover, captures anions, accelerates lithium-ion transport, and prevents the harmful intermediates (like O₂^– or LiO₂), which can drastically degrade the organic electrolyte. Furthermore, the insulating characteristics of the ZIF-8@GF membrane deter direct electron transport to ZIF-8 nanoparticles during lithium peroxide formation, thus ensuring uninterrupted access to catalytic anion trapping sites.

O3-type layered oxide materials are considered one of the most promising cathode materials for sodium-ion batteries due to their high capacity. However, the structural evolution of the O3-type layered oxide during cycling is more complex, exhibiting poorer structural reversibility. In order to achieve a high electrochemical performance of O3-type sodium-ion cathode materials, we adopted a high-entropy strategy to realize multielement codoping of Mg, Co, and Ti into the transition metal layer of O3-type NaNi_0.4Fe_0.2Mn_0.4O₂ and prepared a high-entropy cathode material of NaNi_0.35Mg_0.05Fe_0.15Co_0.05Mn_0.35Ti_0.05O₂ (NMFCMT-2). The transition metal layer doped with multiple elements Mg, Co, and Ti not only stabilizes the crystal structure and widens the layer spacing but also weakens the Na–O bonding, thereby facilitating sodium-ion diffusion and mitigating volume changes during the charge–discharge process. In situ XRD results show that this strategy can delay the phase transition of O3–P3 and realize the phase transition of P3–O3 in advance during the discharge process so that NMFCMT-2 can maintain the O3 phase to a greater extent during the cycles. The results show that the capacity retention rate was 80.6% after 200 cycles at 1C and 88.6% after 200 cycles at 5C. In addition, its high voltage cycling stability is also significantly improved compared to the pristine NaNi_0.4Fe_0.2Mn_0.4O₂.

In this study, uniform and compact ultrasonically spray-coated 1.6 eV CsFAPbIBr films were developed by precisely controlling the wet-to-dry film transition. Achieving both fast nucleation─essential for film compactness─and a smooth wet-to-dry transition to enhance uniformity is particularly challenging in the ultrasonic spray coating of perovskite (PSK). The rapid solvent evaporation via gas quenching, required for achieving fast nucleation, can induce fluid flows that disrupt the film’s uniformity, especially in ultrasonic spray coating processes, where the wet film often exhibits thickness variations. Key parameters─including substrate temperature, N₂ gun distance, natural drying time, nozzle path speed, and cosolvent ratio─were adjusted to control the wet-to-dry film transition and suppress unwanted fluid flows. These fluid flows are triggered by the impact of the N₂ flow during gas quenching and are also potentially driven by surface tension gradients. The optimized conditions resulted in a uniform and pinhole-free PSK layer. Integrating the developed PSK film in a completely scalable device stack resulted in uniform performance across the sample’s area. The devices showed reproducible power conversion efficiency (PCE) values centered around 17%.

Silicon suboxide (SiO_x) is recognized as a promising anode material for lithium-ion batteries (LIBs) because of its higher specific capacity in comparison to graphite and better capacity retention in comparison to pure Si. However, the immense volume expansion and formation of inert lithium oxide (Li₂O) during repeated lithiation and delithiation largely impede its practical application. In this study, we propose a combined metal activation and N-doped carbon layer coating strategy to overcome these obstacles. Extensive experimental characterization and theoretical calculation results disclose that the incorporation of Co nanoparticles into SiO_x can not only boost the charge transfer kinetics but also activate the reversible conversion of Li₂O to provide additional capacity. By further incorporating an N-doped carbon layer on the SiO_x surface, the volume expansion of SiO_x is greatly suppressed. As a consequence, the regulated SiO_x anode displays a high reversible specific capacity of 627.8 mA h g^–1 after 100 cycles at 0.1 A g^–1. By an increase in the current density to 1 A g^–1, a reversible specific capacity of 495.4 mA h g^–1 is retained after 500 cycles. This work provides an effective avenue to simultaneously activate the inert Li₂O and inhibit the volume change for the SiO_x anode, which is beneficial for further development of high-performance LIBs.

Manganese dioxide (MnO₂) emerges as a promising cathode active material for aqueous zinc-ion batteries (AZIBs) due to its inherent safety and environmental friendliness. However, various crystalline forms of MnO₂ (e.g., α- or β-MnO₂) exhibit low structural stability or limited ion diffusion, resulting in poor cycling stability, particularly under high current density. Herein, a MnO₂ polymorph (PM-MnO₂) is constructed via the in situ doping of trace potassium ions (K⁺) into β-MnO₂, remarkably addressing these challenges. By leveraging the high structural stability of the β-MnO₂ phase and the facilitated ion diffusion in α-MnO₂ phases, PM-MnO₂ with a low atomic ratio of K to Mn of only 0.02 demonstrates excellent electronic and ionic conductivity, thereby achieving enhanced charge storage kinetics as a cathode material. The assembled AZIBs exhibit a high specific capacity of 295.3 mA h g^–1 at a charge–discharge rate of 10 C (1 C = 308 mA h g^–1), with an average capacity decay rate of only 0.017% per cycle over 3000 cycles, indicating significant potential for practical applications. This research provides experimental insight into how K⁺ doping affects the crystal structure of MnO₂ and highlights the crucial role of polymorphic materials in enhancing the performance of MnO₂-based AZIBs.

Nitrogen-doped carbon nanotubes (N-CNTs) present significant advantages in energy applications; however, their incorporation into functional systems remains challenging, primarily due to issues such as pronounced agglomeration and insufficient interfacial interactions with host materials. In this study, we present a versatile in situ growth strategy for N-CNTs using a liquid-phase precursor and silica nanospheres as sacrificial templates. The silica nanospheres are demonstrated to play a pivotal role in promoting the controlled growth of N-CNTs during the pyrolysis of an ionic liquid, thereby effectively mediating the composition and structural evolution of the resulting carbon material. This method achieves a nitrogen doping content of 5.5 wt%, predominantly consisting of pyridinic-N and pyrrolic-N species, and a specific surface area of 698.7 m² g^–1, both of which contribute to significantly enhanced oxygen reduction reaction (ORR) electrocatalytic activity under alkaline conditions. The proposed strategy offers a scalable and facile route for integrating N-CNTs into carbon-based electrocatalysts, providing significant potential for advanced applications in fuel cells and metal-air batteries.

The conversion of CO₂ to CH₄ by using solar energy represents a promising carbon-neutral process. Nonetheless, some critical issues, including the inherent stability of CO₂, the presence of erratic intermediates, and intricate electron transfer processes, pose significant challenges to the photocatalytic conversion of CO₂ to CH₄. Therefore, how to introduce specific active metals as an innovative site has been recognized as one effective approach to improve the photocatalytic performance of catalysts. Here, we designed and incorporated Cu sites into Cs₄CdBi₂Cl₁₂ microcrystals for the first time, aiming to produce CH₄ with high selectivity by adjusting the CO₂ reduction pathway. Among the synthesized microcrystals, the Cs₄Cd_0.8Cu_0.2Bi₂Cl₁₂ exhibited superior visible photocatalytic performance, achieving CO and CH₄ yields of 1.54 and 8.78 μmol/g, respectively, with CH₄ electron selectivity as high as 95.78%. Additionally, we utilized in situ Fourier transform spectroscopy to elucidate the mechanism underlying the photoreduction of CO₂ to CH₄. By introducing a novel active site, this study opens up a new avenue for the development of photocatalysts featuring highly selective reduction of CO₂ to CH₄.

Lithium/carbon fluoride (Li/CF_x) primary batteries have attracted wide attention because of their high energy density. However, their application in high-power devices is severely hindered by the retarded reaction kinetics caused by lithium fluoride (LiF) accumulation and difficult desolvation, which is further intensified by low temperature. In this work, an electrolyte strategy has been proposed targeting the kinetic issues. The methyl acetate (MA) low-temperature solvent weakens the Li⁺ coordination and facilitates the Li⁺ desolvation, while crown ether provides a LiF removal effect through its complexing capability. After comprehensive optimization, the benzo-12-crown-4 (B12C4)- and MA-containing electrolyte significantly enhances the rate performance as well as low-temperature output of the CF_x cathode, endowing it with excellent wide-temperature adaptability. This work not only greatly improves the electrochemical property of the CF_x electrode but also provides an alternative electrolyte strategy for all-climate and high-power/energy Li/CF_x cells.

The reliable use of lead-based organic-inorganic perovskite materials in optoelectronic devices is restricted due to their toxic as well as degrading behavior in an ambient atmosphere. Hence, the bismuth-based perovskites have shown potential applications in multijunction perovskite-perovskite-silicon tandem solar cells due to their less toxic and environmentally friendly behavior. Nevertheless, the power conversion efficiency of Bi-related perovskite solar cells is very small compared with solar cells based on Pb-based perovskite, motivating researchers for the fundamental understanding of film formation of Bi-based perovskites as well as energy-level pinning in devices, which is of prime importance. Band-gap pinning can be achieved by tailoring through various types of doping. Herein, MA₃Bi₂I₉ is doped with various concentrations of CsBr. The doped films of MA₃Bi₂I₉ were characterized with the help of XRD, FESEM, UV–visible absorption, and Raman spectroscopic techniques. The observations reveal that doping through CsBr changes the band gap of pristine MA₃Bi₂I₉ from ∼2.05 to ∼2.24 eV with the variation in concentration of dopant from ∼0.05 to ∼0.15%.

Herein, Ba₂AgSi₃ thin films were fabricated by molecular beam epitaxy and their thermoelectric and electrical properties were investigated through experimental and computational approaches. The conductivity type of Ba₂AgSi₃ thin films varied with different Ba/Si supply ratios. Specifically, Si-poor thin films exhibited p-type conductivity, whereas Si-rich thin films exhibited n-type conductivity. Furthermore, a p-type thin film with a Ba-to-Si deposition rate ratio of 3.2 was epitaxially grown on a Si(111) substrate, which showed a high Seebeck coefficient of 296 μV K^–1 and a high power factor of 250 μW m^–1 K^–2 at 311 K. First-principles calculations were performed to study the conductivity type and formation energy of Ba₂AgSi₃ when one atom in its structure was substituted by a group 13 (B, Al, Ga, or In) or 15 (P, As, or Sb) element. Calculation results indicated that substituting Si sites with B, Al, Ga, or In resulted in a Fermi level shift and p-type conductivity, and substituting Si sites with P, As, or Sb resulted in n-type conductivity. Conversely, the substitution of Ba or Ag sites with a group 13 or 15 element resulted in metallic properties and unstable modulation of the conductivity type. A comparison of the formation energies of impurity-doped Ba₂AgSi₃ revealed that B was the most suitable dopant for fabricating p-type Ba₂AgSi₃ among all group 13 elements, and all group 15 elements (P, As, and Sb) were suitable for fabricating n-type Ba₂AgSi₃. Our findings provide a basis for preparing customizable Ba₂AgSi₃-based thermoelectric materials.

The growing demand for electric vehicles is driving the development of next-generation batteries with higher energy densities, surpassing the limitations of conventional graphite anodes. Lithium metal-based anodes present promising solutions due to their high theoretical capacity (3860 mAh g^–1) and the lowest electrochemical potential (−3.04 V versus standard hydrogen electrodes). However, practical application is hindered by challenges, such as dendrite growth, volume expansion, and unstable solid electrolyte interphase (SEI) formation. This study introduces a straightforward calendering coating process to apply a lithiophilic gold (Au) layer on a copper current collector (i.e., Cu mesh), utilizing established electrode manufacturing techniques. The Au-coated Cu mesh electrode significantly reduces the lithium nucleation overpotential, promoting uniform lithium deposition and growth. Electrochemical characterization revealed that the Au-coated Cu mesh achieved a high coulombic efficiency (CE) of 93.76% after 50 cycles in half-cells with 1 mAh cm^–2 lithium plating and 91.58% after 50 cycles with 2 mAh cm^–2 lithium plating. The findings demonstrate that the simple calendering Au coating method effectively mitigates volume expansion, promotes stable SEI formation, and suppresses lithium dendrite growth, offering a scalable approach to advancing anode-free lithium metal battery technology. This study provides valuable insights for designing process-compatible protective layers for anode-free lithium metal batteries.

Understanding electron transfer reactions in phenoxazine aqueous-soluble electroactive materials is crucial for developing flow battery (FB) electrolytes, especially for the positive side. Here, we prepared a water-soluble phenoxazine methyl celestine blue compound (mCB) to demonstrate its relatively high redox potential and study its reversible redox chemistry in aqueous KCl solutions. This flow battery (FB) electrolyte exhibited full capacity retention when tested in a symmetrical cell operated at 86% capacity during 55 charge–discharge cycles. The stability of the radical species formed during the one-electron reduction process of mCB (to obtain the positive electrolyte of the FB cell) was also characterized by cyclic voltammetry and electron paramagnetic resonance (EPR) spectroscopy. This electrolyte was also tested against a viologen-based negolyte, and the detected capacity loss (after 55 cycles) was related to a degradation mechanism of the mCB compound undergoing proton oxidation reactions. The experimental results suggest that a more exhaustive characterization by cyclic voltammetry be considered when analyzing FB electrolytes, in order to also take into account the possible effect of inner-sphere electron transfer reactions on the reaction mechanism and its electrochemical parameters.