We illustrate the development of NaDyF₄–NaGdF₄ core–shell nanoparticles (NPs) for targeting prostate cancer cells using a preclinical 9.4 T magnetic resonance imaging (MRI) of live animals. The NPs composed of paramagnetic Dy³⁺ and Gd³⁺ (T₂- and T₁-contrast agents, respectively) demonstrate proton relaxivities of r₁ = 20.2 mM^–1 s^–1 and r₂ = 32.3 mM^–1 s^–1 at clinical 3 T and r₁ = 9.4 mM^–1 s^–1 and r₂ = 144.7 mM^–1 s^–1 at preclinical 9.4 T. The corresponding relaxivity values per NP are r₁ = 19.4 × 10⁵ mM_NP^–1 s^–1 and r₂ = 33.0 × 10⁵ mM_NP^–1 s^–1 at 3 T and r₁ = 9.0 × 10⁵ mM_NP^–1 s^–1 and r₂ = 147.0 × 10⁵ mM_NP^–1 s^–1 at 9.4 T. In vivo active targeting of human prostate tumors grown in nude mice revealed docking of anti-prostate-specific membrane antigen (PSMA) antibody-tagged NPs at tumor sites post-24 h of their intravenous injection. On the other hand, in vivo passive targeting showed preferential accumulation of NPs at tumor sites only within 2 h of their injection, ascribed to the enhanced permeation and retention effect of the tumor. A biodistribution study employing the harvested organs of mice, post-24 h injection of NPs, quantified active targeting as nearly twice as efficient as passive targeting. These outcomes provide potential opportunities for noninvasive diagnosis using NaDyF₄–NaGdF₄ core–shell NPs for target-specific MRI.

Burn wounds are susceptible to microbial invasion from both resident and exogenous bacteria, which becomes a critical public health issue and causes substantial economic burden. There is a perceived demand to produce new antimicrobial wound dressings that hinder bacterial colonization while accelerating the healing process and hence would provide an improved standard of care for patients. Since ancient times, herbal extracts from medicinally important plants have extensively been used for treating burn injuries. This work reports the utility of electrospun nanofibers containing plant extracts and antibiotics combination as a multifunctional scaffold for treating second-degree burns. First, we determined the various components of plant extracts from Gymnema sylvestre by two different processing methods and their synergism with minocycline antibiotics. Then, we prepared core–shell nanofibrous dressings with poly-ε-caprolactone/gelatin laden with minocycline hydrochloride as a shell and gelatin infused with G. sylvestre extracts (ultrasound-assisted extracts and cold macerated extracts) as the core using coaxial electrospinning. The electrospun nanofibers displayed a smooth, continuous, and bead-free morphology with adequate wettability. The presence of extract components in the core–shell nanofibers resulted in enhanced mechanical properties when compared to pristine mats. The core–shell structures resulted in sustained release of the bioactive components when compared to nanofiber blends. Core–shell nanofiber mats containing plant extracts and antibiotic combinations displayed potent antimicrobial and antibiofilm properties while promoting the spread and proliferation of skin cells when compared to pristine mats. In a porcine model of cutaneous second-degree burns, we showed that wounds treated with the antimicrobial dressing improved re-epithelialization and collagen organization in comparison to untreated wounds.

The purpose of the present study is to characterize poly(d,l-lactide-co-glycolide) (PLGA) composite microcarriers for vascular endothelial growth factor (VEGF) delivery. To reduce the initial burst release and protect the bioactivity, VEGF is encapsulated in soybean l-α-phosphatidylethanolamine (PE) and l-α-phosphatidylcholine (PC) anhydrous reverse micelle (VEGF-RM) nanoparticles. Also, mesoporous nano-hexagonal Mg(OH)₂ nanostructure (MNS)-loaded PE/PC anhydrous reverse micelle (MNS-RM) nanoparticles are synthesized to suppress the induced inflammation of PLGA acidic byproducts and regulate the release profile. The flow-focusing microfluidic geometry platforms are used to fabricate different combinations of PLGA composite microspheres (PLGA-CMPs) with MNSs, MNS-RM, VEGF-RM, and native VEGF. The essential parameters of each formulation, such as release profiles, encapsulation efficacy, bioactivity, inflammatory response, and cytotoxicity, are investigated by in vitro and in vivo studies. The results indicate that generated acidic byproducts during the hydrolytic degradation process of PLGA can be buffered, and pH values inside and outside microspheres can remain steady during degradation by MNSs. Furthermore, the significant improvement in the stability of the encapsulated VEGF is confirmed by the bioactivity assay. In vitro release study shows that the VEGF initial burst release is well minimized in the present microcarriers. The present monodisperse PLGA-CMPs can be widely used in various tissue engineering and therapeutic applications.

Self-assembly of thermally responsive polypeptides into unique nanostructures offers intriguing attributes including dynamic physical dimensions, biocompatibility, and biodegradability for the smart bio-nanomaterials. As elastin-based polypeptide (EBP) fusion proteins with lower critical solution temperature (LCST) are studied as drug delivery systems, EBP block copolypeptides with the resilin-based polypeptide (RBP) displaying an upper critical solution temperature (UCST) have been of great interest. In this study, we report thermally triggered, dynamic self-assembly of EBP- and RBP-based diblock copolypeptides into switched nanostructures with reversibility under physiological conditions. Molecular DNA clones encoding for the EBP–RBP diblocks at different block length ratios were biosynthesized via recursive directional ligation and overexpressed, followed by nonchromatographic purification by inverse transition cycling. Genetically engineered diblock copolypeptides composed of the EBP with an LCST and the RBP with a UCST showed converse phase transition behaviors with both a distinct LCST and a distinct UCST (LCST < UCST). As temperature increased, three phases of these EBP–RBP diblocks were observed: (1) self-assembled micelles or vesicles below both LCST and UCST, (2) whole aggregates above LCST and below UCST, and (3) reversed micelles above both LCST and UCST. In conclusion, these stimuli-triggered, dynamic protein-based nanostructures are promising for advanced drug delivery systems, regenerative medicine, and biomedical nanotechnology.

Mimicking nativelike metabolic zonation is indispensable to develop an efficient bioartificial liver model, as it facilitates physiological cues, hepatocyte polarity, and phenotypic functions. The present study shows the first evidence of hepatocyte metabolic heterogeneity in an in vitro liver model encompassing liver extracellular matrix (ECM)-functionalized silk scaffolds (LECM-SF) by altering ECM proportion. Upon static culture, individual LECM-SF scaffold supports differential synthetic and metabolic functions of cultured primary neonatal rat hepatocytes (PNRHs), owing to discrete biophysical attributes. A single in vitro liver system comprising PNRHs seeded LECM-SF scaffolds assisting periportal to pericentral gradient functions is stacked and matured in a perfusion bioreactor to simulate oxygen gradient. The scaffold with high ECM supports periportal-specific albumin synthesis, urea secretion, and bile duct formation, albeit scaffold with low ECM supports pericentral-specific cytochrome P450 activity. Extensive physicochemical characterizations confirmed the stability and interconnected porous network of scaffolds, signifying cellular infiltration and bidirectional nutrient diffusion. Furthermore, scaffolds demonstrate minimal thrombogenicity, reduced foreign-body response, and enhanced pro-remodeling macrophage activation, supporting constructive tissue remodeling. The developed liver model with zone-specific functions would be a promising avenue in bioartificial liver and drug screening.

For site-specific diseases such as atherosclerosis, it is desirable to noninvasively and locally deliver therapeutics for extended periods of time. High-intensity focused ultrasound (HIFU) provides targeted drug delivery, yet remains unable to sustain delivery beyond the HIFU treatment time. Furthermore, methods to validate HIFU-enhanced drug delivery remain limited. In this study, we report on HIFU-targeted implantation of degradable drug-loaded sound-sensitive multicavity PLGA microparticles (mcPLGA MPs) as a theranostic agent for the treatment of arterial lesions. Once implanted into the targeted tissue, mcPLGA MPs eluted dexamethasone for several days, thereby reducing inflammatory markers linked to oxidized lipid uptake in a foam cell spheroid model. Furthermore, implanted mcPLGA MPs created hyperechoic regions on diagnostic ultrasound images, and thus noninvasively verified that the target region was treated with the theranostic agents. This novel and innovative multifunctional theranostic platform may serve as a promising candidate for noninvasive imaging and treatment for site-specific diseases such as atherosclerosis.

pH-responsive smart gating membranes were developed using a two-step fabricating process. In the first step, a porous polyimide (PI) support membrane with ordered, regular, and well-defined pores was obtained with a 248 nm KrF excimer laser using a lithography technique. The porous membranes were then grafted with poly(acrylic acid) (PAAc) hydrogel by free radical polymerization using the same excimer laser. The number of pulses and frequency could be varied to obtain a range of water permeabilities. Permeability of membrane changed significantly due to swelling and deswelling of PAAc inside the pores at pH 7 and pH 3, respectively. These hydrogel networks were firmly grafted inside pores and remained mechanically intact even after using high pressure during permeability studies. PAAc grafting was confirmed using ATR-FTIR. PAAc hydrogel distribution inside membrane pores was analyzed using SEM and fluorescence microscopy. To quantify the amount of polymer grafted, TGA studies were carried out. Diffusion studies were also carried out using caffeine as a drug molecule to evaluate the application of membrane in drug delivery devices. The linear drug release profile obtained from the study confirmed the potential application of membrane for drug delivery purposes. Results obtained also suggest that the fabrication method developed is fast, efficient, solvent-free, and economical.

Most cancers contain abundant tumor-associated macrophages (TAMs). TAMs usually display a tumor-supportive M2-like phenotype; they promote tumor growth and influence lymphocyte infiltration, leading to immunosuppression. These properties have made TAMs an attractive cancer immunotherapy target. One promising immunotherapeutic strategy involves switching the tumor-promoting immune suppressive microenvironment by reprogramming TAMs. However, clinical trials of M2-like macrophage reprogramming have yielded unsatisfactory results due to their low efficacy and nonselective effects. In this article, we describe the development of M2-like macrophage-targeting nanoparticles (PNP@R@M-T) that efficiently and selectively deliver drugs to 58% of M2-like macrophages, over 39% of M1-like macrophages, and 32% of dendritic cells within 24 h in vivo. Compared with the control groups, administration of PNP@R@M-T dramatically reprogrammed the M2-like macrophages (51%), reduced tumor size (82%), and prolonged survival. Our findings indicate that PNP@R@M-T nanoparticles provide an effective and selective reprogramming strategy for macrophage-mediated cancer immunotherapy.

A dual-response (near-infrared, alternating magnetic field) multifunctional nanoplatform was developed based on urokinase plasminogen activators (uPA)-loaded metal–organic-framework (MOF)-derived carbon nanomaterials (referred to uPA@CFs below) for thrombolytic therapy. uPA loaded in mesoporous CFs could be released under the action of near-infrared (NIR)-mediated photothermy to achieve superficial thrombolysis. More importantly, with the assistance of alternating magnetic field (AMF), this system could also precisely heat the thrombosis in the deep tissue area. Quantitative experiments proved that the thrombolytic efficiency of this dual-response system at deep venous thrombosis was nearly 6 times than that of NIR alone. This is the first application that MOF-derived carbon nanomaterials in the field of targeted thrombolysis. To our delight, the MOF-derived carbon nanomaterials (CFs) not only maintained the drug-carrying capacity, but also endowed CFs with reliable magnetic targeting ability. More encouragingly, the CFs also showed extraordinary angiogenic performance, thus opening up the prospect of its clinical application.

Viscoelasticity, a time-scale mechanical feature of the native extracellular matrix (ECM), is reported to play crucial roles in plentiful cellular behaviors, whereas its effects on neuronal behavior and the underlying molecular mechanism still remain obscure. Challenges are faced in the biocompatible synthesis of neural ECM-mimicked scaffolds solely controlled with viscoelasticity and due to the lack of suitable models for neurons–viscoelastic matrix interaction. Herein, we report difunctional hyaluronan–collagen hydrogels prepared by a static–dynamic strategy. The hydrogels show aldehyde concentration-dependent viscoelasticity and similar initial elastic modulus, fibrillar morphology, swelling as well as degradability. Utilizing the resulting hydrogels, for the first time, we demonstrate matrix viscoelasticity-dependent neuronal responses, including neurite elongation and expression of neurogenic proteins. Then, a motor-clutch model modified with a tension dissipation component is developed to account for the molecular mechanism for viscoelasticity-sensitive neuronal responses. Moreover, we prove enhanced recovery of rat spinal cord injury by implanting cell-free viscoelastic grafts. As a pioneer finding on neurons–viscoelastic matrix interaction both in vitro and in vivo, this work provides intriguing insights not only into nerve repair but also into neuroscience and tissue engineering.

The pseudovirus strategy makes studies of highly pathogenic viruses feasible without the restriction of high-level biosafety facility, thus greatly contributing to virology and is used in the research studies of SARS-CoV-2. Here, we generated a dual-color pseudo-SARS-CoV-2 virus using a human immunodeficiency virus-1 pseudovirus production system and the SARS-CoV-2 spike (S) glycoprotein, of which the membrane was labeled with a lipophilic dye (DiO) and the genomic RNA-related viral protein R (Vpr) of the viral core was fused with mCherry. With this dual-color labeling strategy, not only the movement of the whole virus but also the fate of the labeled components can be traced. The pseudovirions were applied to track the viral entry at a single-particle level in four types of the human respiratory cells: nasal epithelial cells (HNEpC), pulmonary alveolar epithelial cells (HPAEpiC), bronchial epithelial cells (BEP-2D), and oral epithelial cells (HOEC). Pseudo-SARS-CoV-2 entered into the host cell and released the viral core into the cytoplasm, which clearly indicates that the host entry mainly occurred through endocytosis. The infection efficiency was found to be correlated with the expression of the known receptor of SARS-CoV-2, angiotensin-converting 2 (ACE2) on the host cell surface. We believe that the dual-color fluorescently labeled pseudovirus system created in this study can be applied as a useful tool for many purposes in SARS-CoV-2/COVID-19.

Benefiting from superior programmability and good biocompatibility, DNA nanomaterials have received considerable attention with promising prospects in biological detection applications. However, their poor stability and operability severely impede further development of the applications of DNA nanomaterials. Here, a thermally stable DNA nanomesh structure is integrated into a microfluidic chip. The specificity of the nucleic acid microfluidic capture device could reach the single-base mismatch level while capturing the ssDNA sample. The microfluidic chip provides a closed environment for the DNA nanomesh, giving the device excellent storage stability. After 6 months of storage at room temperature, the device still has a specific capture function on ssDNA samples with low concentration. The specific nucleic acid microfluidic capture device can be applied to the enrichment of ctDNA in the future and contribute to the early diagnosis of cancer.

The ability of mimicking the extracellular matrix architecture has gained electrospun scaffolds a prominent space into the tissue engineering field. The high surface-to-volume aspect ratio of nanofibers increases their bioactivity while enhancing the bonding strength with the host tissue. Over the years, numerous polyesters, such as poly(lactic acid) (PLA), have been consolidated as excellent matrices for biomedical applications. However, this class of polymers usually has a high hydrophobic character, which limits cell attachment and proliferation, and therefore decreases biological interactions. In this way, functionalization of polyester-based materials is often performed in order to modify their interfacial free energy and achieve more hydrophilic surfaces. Herein, we report the preparation, characterization, and in vitro assessment of electrospun PLA fibers with low contents (0.1 wt %) of different curcuminoids featuring π-conjugated systems, and a central β-diketone unit, including curcumin itself. We evaluated the potential of these materials for photochemical and biomedical purposes. For this, we investigated their optical properties, water contact angle, and surface features while assessing their in vitro behavior using SH-SY5Y cells. Our results demonstrate the successful generation of homogeneous and defect-free fluorescent fibers, which are noncytotoxic, exhibit enhanced hydrophilicity, and as such greater cell adhesion and proliferation toward neuroblastoma cells. The unexpected tailoring of the scaffolds’ interfacial free energy has been associated with the strong interactions between the PLA hydrophobic sites and the nonpolar groups from curcuminoids, which indicate its role for releasing hydrophilic sites from both parts. This investigation reveals a straightforward approach to produce photoluminescent 3D-scaffolds with enhanced biological properties by using a polymer that is essentially hydrophobic combined with the low contents of photoactive and multifunctional curcuminoids

Polyacrylamide-based hydrogels are widely used as potential candidates for cartilage replacement. However, their bioapplicability is sternly hampered due to their limited mechanical strength and puncture resistance. In the present work, the strength of polyacrylamide (PAM) hydrogels was increased using titanium oxide (TiO₂) and carbon nanotubes (CNTs) separately and a combination of TiO₂ with CNTs in a PAM matrix, which was interlinked by the bonding between nanoparticles and polymers with the deployment of density functional theory (DFT) approach. The synergistic effect and strong interfacial bonding of TiO₂ and CNT nanoparticles with PAM are attributed to high compressive strength, elastic modulus (>0.43 and 2.340 MPa, respectively), and puncture resistance (estimated using the needle insertion test) for the PAM–TiO₂–CNT hydrogel. The PAM–TiO₂–CNT composite hydrogel revealed a significant self-healing phenomenon along with a sign toward the bioactivity and cytocompatibility by forming the apatite crystals in simulated body fluid as well as showing a cell viability of ∼99%, respectively. Furthermore, for new insights on interfacial bonding and structural and electronic features involved in the hydrogels, DFT was used. The PAM–TiO₂–CNT composite model, constructed by two interfaces (PAM–TiO₂ and PAM–CNT), was stabilized by H-bonding and van der Waals-type interactions. Employing the NCI plot, HOMO–LUMO gap, and natural population analysis tools, the PAM–TiO₂–CNT composite has been found to be most stable. Therefore, the prepared polyacrylamide hydrogels in combination with the TiO₂ and CNT can be a remarkable nanocomposite hydrogel for cartilage repair applications.

Abdominal sections of honeybees undergo numerous reciprocating motions during their lifetime. However, the overlapped contact areas adjacent to the abdominal sections have a shallow wear extent, a physical mechanism that remains obscure to date. Therefore, this study explored a biofrictional reduction model based on a solid surface texture and the hairy surface of the honeybee abdomen. We collected honeybee samples and observed their abdomens using a camera (Zeiss Stemi 508). Subsequently, we sliced these samples using a microtome and detected their microscopic friction. The exterior surface of the honeybee abdomen was not smooth but was distributed with a dense microvilli structure, which played a vital role in adjusting the friction reduction characteristics between the abdominal sections. When the adjacent abdominal sections moved relatively to each other, their upper and lower surfaces were not in direct rigid contact. Briefly, this study shows that the microscale hair arrays on the surface of the posterior abdominal segment can significantly reduce real contact area and friction, which considerably decreases wear or abrasion. The friction reduction mechanism alleviates the abrasion during the relative bending movement and saves a large amount of energy, which is essential for the honeybees’ daily activities. This microtexture compliance friction reduction characteristic could be used to fabricate hierarchical surfaces for long-lasting friction reduction mechanisms, which increase the life of soft devices, including soft actuators and hinges.

Sonodynamic therapy (SDT) is a promising method for tumor treatment, but self-quenching property, low loading efficiency of sonosensitizers, and hypoxia tumor microenvironment (TME) hinder the efficiency of SDT. Herein, an erythrocyte membrane (EM)-camouflaged metal–organic framework (MOF) of PCN-224 nanoparticles (NPs) integrated with platinum (Pt) NPs as well as glucose oxidase (GOx) has been developed to overcome these limits. Porphyrin-based PCN-224 NPs are synthesized as a sonosensitizer with a large amount of well-organized porphyrin molecules while simultaneously acting as the nanocarriers (NCs) for Pt NPs and GOx. When the NCs are internalized by tumor cells, Pt NPs on their surface are able to utilize endogenous hydrogen peroxide (H₂O₂) to produce oxygen for the relief of tumor hypoxia, thus enhancing the SDT effect. After EM cloaking, the longer circulation time can improve biocompatibility in vivo and enhance accumulation in tumor tissue. Loaded GOx is beneficial to local glucose consumption and can realize the tumor starvation therapy effect. Consequently, these multifunctional NCs show amplified synergistic therapeutic effects of tumor SDT and starvation therapy, which can efficiently inhibit the tumor growth.

The isolation and detection of rare circulating tumor cells (CTCs) from patient peripheral blood can help early diagnosis of cancer and evaluation of therapeutic outcomes. At present, most of the available strategies for enriching CTCs face serious problems with purity due to the nonspecific interactions between the capture medium and leukocytes. Inspired by the immune evasion ability of homologous red blood cells (RBCs), we modified the tumor-targeting molecule folic acid (FA) on the surface of RBCs by hydrophobic interactions. Under the treatment of polybrene, the charges on the surface of RBCs are neutralized, which reduces the mutual repulsion force. Furthermore, RBCs treated with polyethylene also have excellent deformability, thereby enabling engineered RBCs to form a dense bionic layer on the adhesive glass slide, which can greatly inhibit the nonspecific adhesion of leukocytes. The bionic layer can achieve high-purity enrichment of tumor cells in phosphate-buffered saline (PBS), and we can achieve high-activity release in plasma. The cell count showed over 80% capture efficiency and over 70% release rate, and the purity of CTCs obtained in the artificial blood sample after release was higher than 90%. The RBC bionic surface coating is notably cost-effective and highly applicable for CTC isolation in clinic practice, and thus provides new prospects for designing cell–material interfaces for advanced cell-based biomedical studies in the future.

Articular cartilage has very poor intrinsic healing ability and its repair remains a significant clinical challenge. To promote neocartilage regeneration, we fabricated two collagen (Col) scaffolds functionalized with a porcine decellularized extracellular matrix (dECM) in the forms of particle and solution named pE-Col and sE-Col, respectively. Their differences were systematically compared, including the biochemical compositions, scaffold properties, cell–material interactions, and in situ cartilage regeneration. While it is demonstrated that both forms of dECM could enhance the cell recruitment, proliferation, and chondrogenesis of bone marrow stem cells (BMSCs) in vitro, better performance was seen in the sE-Col group, which could quickly provide a more favorable chondrogenic microenvironment for endogenous BMSCs. The superiority of sE-Col was also proved by our in vivo study, which showed that the sE-Col scaffold achieved better structural hyaline-like neocartilage formation and subchondral bone repair compared to the pE-Col scaffold, according to the gross morphology, biological assessment, and micro-CT imaging analysis. Together, this study suggests that the sE-Col scaffold holds great potential in developing the one-step microfracture-based strategy for cartilage repair and also reminds us that despite dECM being a promising biomaterial in tissue engineering, the optimization of the proper processing methodology would be a crucial consideration in the future design of dECM-based scaffolds in articular cartilage regeneration.

Rechargeable Mg-ion batteries typically suffer from either rapid passivation of the Mg anode or severe corrosion of the current collectors by halogens within the electrolyte, limiting their practical implementation. Here, we demonstrate the broadly applicable strategy of forming an artificial solid electrolyte interphase (a-SEI) layer on Mg to address these challenges. The a-SEI layer is formed by simply soaking Mg foil in a tetraethylene glycol dimethyl ether solution containing LiTFSI and AlCl₃, with Fourier transform infrared and ultraviolet–visible spectroscopy measurements revealing spontaneous reaction with the Mg foil. The a-SEI is found to mitigate Mg passivation in Mg(TFSI)₂/DME electrolytes with symmetric cells exhibiting overpotentials that are 2 V lower compared to when the a-SEI is not present. This approach is extended to Mg(ClO₄)₂/DME and Mg(TFSI)₂/PC electrolytes to achieve reversible Mg plating and stripping, which is not achieved with bare electrodes. The interfacial resistance of the cells with a-SEI protected Mg is found to be two orders of magnitude lower than that with bare Mg in all three of the electrolytes, indicating the formation of an effective Mg-ion transporting interfacial structure. X-ray absorption and photoemission spectroscopy measurements show that the a-SEI contains minimal MgCO₃, MgO, Mg(OH)₂, and TFSI^–, while being rich in MgCl₂, MgF₂, and MgS, when compared to the passivation layer formed on bare Mg in Mg(TFSI)₂/DME.

Despite the fact that power conversion efficiency (PCE) has been greatly improved in recent years, perovskite solar cells (PSCs) need to overcome some challenges, like stability, for the commercial application. Herein, an anionic conjugated polyelectrolyte, sulfonic-containing polyfluorene (abbreviated to SPF), has been developed to modify the interface between the electron-transporting layer (ETL) SnO₂ and the optoelectronic active layer MAPbI₃ in the n-i-p cells. After 40 days of storage in atmospheric environment in the dark with exposure to a controlled humidity of about 10%, PCE of the SPF-modified cells with the structure of ITO/SnO₂/SPF/MAPbI₃/spiro-OMeTAD/Au still remained 94% of the initial value. In contrast, the control cell without SPF only remained 31.1% of its initial efficiency after 29 days. The main reason for the stability enhancement is the adjustment of interfacial energy level, the crystallinity enhancement, and the removal of the interfacial defect of the perovskite layer by introducing the hydrophobic and smooth SPF interfacial layer. Deep electrical study on the PSCs discloses that the cell has low carrier transfer resistance, low leakage current density, and minor interfacial charge accumulation. What’s more, the short-circuit current density is improved, and PCE of 20.47% is achieved.

Lithium-based molten salts have attracted significant attention due to their applications in energy storage, advanced fission reactors, and fusion devices. Lithium fluorides and particularly 66.6%LiF–33.3%BeF₂ (Flibe) are of considerable interest in nuclear systems, as they show an excellent combination of favorable heat transfer, neutron moderation, and transmutation characteristics. For nuclear salts, the range of possible local structures, compositions, and thermodynamic conditions presents significant challenges in atomistic modeling. In this work, we demonstrate that atom-centered neural network interatomic potentials (NNIPs) provide a fast method for performing molecular dynamics of molten salts that is as accurate as ab initio molecular dynamics. For LiF, these potentials are able to accurately reproduce ab initio interactions of dimers, crystalline solids under deformation, crystalline LiF near the melting point, and liquid LiF at high temperatures. For Flibe, NNIPs accurately predict the structures and dynamics at normal operating conditions, high-temperature–pressure conditions, and in the crystalline solid phase. Furthermore, we show that NNIP-based molecular dynamics of molten salts are scalable to reach long time scales (e.g., nanosecond) and large system sizes (e.g., 10⁵ atoms) while maintaining ab initio density functional theory accuracy and providing more than 3 orders of magnitude of computational speedup for calculating structure and transport properties.

We studied the electrochemical synthesis of NH₃ on Fe–CuS/C catalysts in an alkaline aqueous solution under ambient conditions. The metal chalcogenide catalyst is active in the nitrogen reduction reaction (NRR) for approximately 45 min with an NH₃ production yield of 16 μg h^–1 cm^–2 at −0.4 V_RHE, while it decomposes to CuO. The rapid degradation of the catalyst hinders the precise investigation of the NH₃ production activity in longer time measurements. Herein, the electrochemical NH₃ production rate is enhanced with increased overpotentials when the degradation effect is mitigated in the measurement, which was difficult to observe in the NRR reports. In the Tafel analysis, the exchange current density, heterogeneous rate constant, and transfer coefficient of the Fe–CuS/C catalyst on the NRR were estimated. When the electrode degradation is mitigated, one of the best NH₃ production activities among the reported metal sulfide electrochemical NRR catalysts is obtained, which is 42 μg h^–1 cm^–2 at −0.6 V_RHE.

The rational design and preparation of hierarchical hollow structures have promising potential in electrochemical energy storage systems. In this paper, double-shell hollow carbon fibers (DSHCFs) with tunable thickness and shell spacing are prepared using hollow electrospun polystyrene fibers as the hard template and in situ coated polypyrrole as the carbon source. The as-prepared DSHCFs with an optimized structure exhibit a submicrometer shell spacing and a nanoscaled shell thickness, which guarantees sufficient contact area with the electrolyte and provides abundant electrochemical active sites for Li⁺ storage. Owing to the unique structural advantages, a DSHCF-based anode shows favorable transport kinetics for both Li⁺ ions and electrons during the lithiation/delithiation process, and a high reversible capacity of 348 mAh g^–1 at 5.0 A g^–1 is well maintained even after 500 cycles with no obvious capacity attenuation. Particular emphasis is given to kinetic Li⁺ storage mechanisms in DSHCFs that are discussed in detail, providing a new avenue for developing high-performance carbon materials for the practical application of energy storage devices.

We evaluated the catalytic performance of the Rh–Fe/Al₂O₃ catalyst during a three-way catalytic reaction and found, by chance, that a part of Fe species was dissolved into the γ-Al₂O₃ support and worked as an oxygen storage material, which adjusts the oxygen concentration around the catalytically active sites to a suitable level for three-way catalysis. In this study, we demonstrated that the Fe-doped γ-Al₂O₃ can reversibly store and release oxygen by the redox of Fe²⁺/Fe³⁺ at the tetrahedral (T_d) site of the spinel structure without its structure deformation. The finding that a spinel-structured metal oxide, Fe-doped γ-Al₂O₃, could work as an oxygen storage material suggested a new opportunity for the development of oxygen storage materials without rare metals.

A simple wet-chemical route for the preparation of core–shell-structured catalysts was developed to achieve high oxygen reduction reaction (ORR) activity with a low Pt loading amount. Nickel nitride (Ni₃N) nanoparticles were used as earth-abundant metal-based cores to support thin Pt layers. To realize the site-selective formation of Pt layers on the Ni₃N core, hydrogen molecules (H₂) were used as a mild reducing agent. As H₂ oxidation is catalyzed by the surface of Ni₃N, the redox reaction between H₂ and Pt(IV) in solution was facilitated on the Ni₃N surface, which resulted in the selective deposition of Pt on Ni₃N. The controlled Pt formation led to a subnanometer (0.5–1 nm)-thick Pt shell on the Ni₃N core. By adopting the core–shell structure, higher ORR activity than the commercial Pt/C was achieved. Electrochemical measurements showed that the thin Pt layer on Ni₃N nanoparticle exhibits 5 times higher mass activity and specific activity than that of commercial Pt/C. Furthermore, it is expected that the proposed simple wet-chemical method can be utilized to prepare various transition-metal-based core–shell nanocatalysts for a wide range of energy conversion reactions.

Volume expansion hinders conversion-type transition-metal oxides (TMOs) as potential anode candidates for high-capacity lithium-ion batteries. While nanostructuring and nanosizing have been employed to improve the cycling stability of TMOs, we show here that both high initial Coulombic efficiency (ICE) and stable cycling reversibility are achieved in the layered compound Li_0.9Nb_0.9Mo_1.1O₆ (L0.9NMO) by inherent properties of the bulk crystal structure. In this model, MoO₆ octahedra as active centers react with lithium ions and endow capacity, while a grid composed of NbO₆ octahedra effectively suppresses the volume expansion, enhances the conductivity, and supports the structural skeleton from collapse. As a result, bulk L0.9NMO not only delivers a high discharge capacity of 1128 mA h g^–1 at 100 mA g^–1 with a considerable ICE of 87% but also exhibits long cycling stability and good rate performance (339 mA h g^–1 after 500 cycles at 1 A g^–1 with an average Coulombic efficiency approaching 100%). The self-confined structure provides a competitive strategy for stable conversion-type lithium storage.

Electrochemical hydrogenation is a challenging technoeconomic process for sustainable liquid fuel production from biomass-derived compounds. In general, half-cell hydrogenation is paired with water oxidation to generate the low economic value of O₂ at the anode. Herein, a new strategy for the rational design of Ru/reduced graphene oxide (Ru/RGO) nanocomposites through a cost-effective and straightforward microwave irradiation technique is reported for the first time. The Ru nanoparticles with an average size of 3.5 nm are well anchored into the RGO frameworks with attractive nanostructures to enhance the furfural’s paired electrohydrogenation (ECH) and electrooxidation (ECO) process to achieve high-grade biofuel. Furfural is used as a reactant with the paired electrolyzer to produce furfuryl alcohol and 2-methylfuran at the cathode side. Simultaneously, 2-furic acid and 5-hydroxyfuroic acid along with plenty of H⁺ and e^– are generated at the anode side. Most impressively, the paired electrolyzer induces an extraordinary ECH and ECO of furfural, with the desired production of 2-methylfuran (yield = 91% and faradic efficiency (FE) of 95%) at X_FF = 97%, outperforming the ECH half-cell reaction. The mechanisms of the half-cell reaction and paired cell reaction are discussed. Exquisite control of the reaction parameters, optimized strategies, and the yield of individual products are demonstrated. These results show that the Ru/RuO nanocomposite is a potential candidate for biofuel production in industrial sectors.

Inorganic lead halide perovskite CsPbIBr₂ possesses good stability with a suitable band gap for tandem solar cells. Decreasing the defect concentration and improving the film quality is crucial to further increase the power conversion efficiency of CsPbIBr₂ solar cells. Here, the crystallization dynamics of CsPbIBr₂ films is regulated by introducing the volatile organic salt, formamidinium acetate (FAAc) into the precursor solution. It is found that FAAc slows the crystallization process of CsPbIBr₂ films and pinhole-free films with large grains and smooth surfaces are obtained. The defect concentration of the films is decreased and the nonradiative recombination is significantly inhibited. By improving the film quality, the FAAc remarkably enhances the efficiency of CsPbIBr₂ solar cells. The champion device delivers a power conversion efficiency of 9.44% and exhibits higher stability than the reference device. This finding provides an effective strategy for reducing defects, suppressing the recombination, and improving the performance of CsPbIBr₂ solar cells.

An ionic liquid (IL) laden metal–organic framework (MOF) sodium-ion electrolyte has been developed for ambient-temperature quasi-solid-state sodium batteries. The MOF skeleton is designed according to a UIO-66 (Universitetet i Oslo) structure. A sodium sulfonic (−SO₃Na) group grafted to the UIO-based MOF ligand improves the Na⁺-ion conductivity. Upon lading with a sodium-based ionic liquid (Na-IL), sodium bis(trifluoromethylsulfonyl)imide (NaTFSI) in 1-n-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide (Bmpyr-TFSI), the Na-IL laden sulfonated UIO-66 (UIOSNa) quasi-solid electrolyte exhibits a Na⁺-ion conductivity of 3.6 × 10^–4 S cm^–1 at ambient temperature. Quasi-solid-state sodium batteries with the Na-IL/UIOSNa electrolyte are demonstrated with a layered Na₃Ni_1.5TeO₆ cathode and sodium-metal anode. The quasi-solid-state Na∥Na-IL/UIOSNa∥Na₃Ni_1.5TeO₆ cells show remarkable cycling performance.

In this study, an NH₃ plasma-treated Cu/HZSM-5 sorbent was introduced to simultaneously remove H₂S and PH₃ in low-temperature and low-oxygen environments. The effects of the Cu loading amounts, modification methods, and plasma-treatment conditions on the adsorption–oxidation performance of the sorbents were investigated. From the performance test results, the sorbent treated by NH₃ plasma with the specific energy input (SEI, electrical input energy to the unit volume of gas) value of 1 J·mL^–1 (Cu/HZSM-5-[S1]) was identified as having the highest breakthrough capacities of 108.9 mg S·g^–1 and 150.9 mg P·g^–1 among all of the materials tested. After three times of regeneration, the sorbent can still maintain the ideal performance. The results of Fourier transform infrared (FT-IR) spectroscopy and CO₂ temperature-programmed desorption (CO₂-TPD) indicated that the NH₃ plasma treatment can introduce amino groups (functional groups) onto the sorbent surface, which greatly increases the number and strength of the basic sites on the sorbent surface. Results of N₂ adsorption/desorption isotherms and scanning electron microscopy–energy dispersive spectroscopy (SEM–EDS) showed that the morphology of the sorbent changed after the plasma treatment, which exposed more active sites (copper species). In situ IR spectra showed that the amino groups are continuously consumed during the reaction process, indicating that these amino groups can help sorbents to capture gas molecules. Moreover, X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) analyses indicated that CuO is the main active species and the consumption of CuO and accumulation of the reaction products on the surface and inner pores of the sorbent are the primary reasons for the deactivation of the sorbent.

Developing a high-performance nonprecious metal electrocatalyst for water splitting is a strong demand for the large-scale application of electrochemical H₂ production. In this work, we design a facile and scalable strategy to activate titanium metal for the hydrogen evolution reaction (HER) in alkaline media through incorporating hydrogen into the α-Ti crystal lattice by H₂ plasma bombardment. Benefiting from the accelerated charge transfer and enlarged electrochemical surface area after H₂ plasma treatment, the H-incorporated Ti shows remarkably enhanced HER activity with a much lower overpotential at −10 mA cm^–2 by 276 mV when compared to the pristine Ti. It is revealed that the retention of the incorporated H(D) atoms in the Ti crystal lattice during HER accounts for the durable feature of the catalyst. Density functional theory calculations demonstrate the effectiveness of hydrogen incorporation in tuning the adsorption energy of reaction species via charge redistribution. Our work offers a novel route to activate titanium or other metals by H incorporation through a controllable H₂ plasma treatment to tune the electronic structure for water splitting reactions.

Excess lead iodide (PbI₂) plays a crucial role in passivating the defects of perovskite films and boosting the power conversion efficiency (PCE) of perovskite solar cells (PSCs). However, the photolysis of PbI₂ is easily triggered by light illumination, which accelerates the decomposition of perovskite materials and weakens the long-term stability of PSCs. Herein, the high light tolerance of lead iodide (PbI₂) is reported by introducing an electron-donor molecule, namely, 2-thiophenecarboxamide (2-TCAm), to strengthen the [PbX₆]^4– frame. Characterization reveals that the retarded decomposition of PbI₂ is attributed to the interactions between Pb²⁺ and the organic functional groups in 2-TCAm as well as the optimized distribution of PbI₂. The crystallization and morphology of 2-TCAm-doped perovskite films are improved simultaneously. The 2-TCAm-based PSCs achieve a 16.8% increase in PCE and nearly 12 times increase in the lifetime as compared to the reference device. The demonstrated method provides insight into the stability of PbI₂ and its influence on PSCs.

Methanol aqueous phase reforming (MAPR) reaction under mild conditions is one of the most practical ways to generate hydrogen (H₂), in which the liquid vaporization unit could be removed by the water phase reforming, making the structure of an in situ H₂ production reactor more compact. In this work, the H₂ production performances of the metal-free catalyst, N-doped carbon dots/g-C₃N₄ (NCDs/g-C₃N₄; CN-x) composites, was investigated for the MAPR reaction under low temperature and normal pressure. The optimized metal-free catalyst (NCDs/g-C₃N₄; CN-0.7) displays a H₂ yield of 19.5 μmol g^–1 h^–1 at 80 °C. More importantly, a clear understanding on the effective MAPR reaction at low temperature and normal pressure was acquired from in situ diffuse reflectance FTIR spectroscopy and the transient photovoltage test. The introduction of NCDs leads to the localization of surface charge, which is beneficial to the selective adsorption and polarization activation of polar molecules on the catalyst surface. This work provides a new strategy for the carbon-based catalyst design of the MAPR reaction at low temperatures.

Designing low-cost preparation of high-activity electrocatalysts with excellent stability is the route one must take to fully realize large-scale application implementation of zinc–air batteries. 3D nitrogen-doped nanocarbons with transition metals or their derivatives encapsulated in show promising potential in the field of non-precious metal oxygen electrocatalysis. Herein, we report a simple, economical, and large-scale production method to construct worm-like porous nitrogen-doped carbon with in situ-grown carbon nanotubes and uniformly embedded Fe/Fe₃C nanoparticles. It not only has high conductivity owing to the nitrogen-doped nature but also has ample active sites and electrolyte diffusion channels benefitting from the uniformly distributed heterostructural Fe/Fe₃C nanoparticles and discrete hierarchically porous structures. When used as catalyst materials for a zinc–air battery, an energy density of 719.1 Wh kg^–1 and a peak power density of 101.3 mW cm^–2 at a 50 mA cm^–2 discharge current density is achieved. Additionally, throughout charging and discharging for 200 cycles at a current density of 20 mA cm^–2, the charge/discharge voltage gap is nearly constant.

Photocatalytic water splitting offers an economic and sustainable pathway for producing hydrogen as a zero-emission fuel, but it still suffers from low efficiencies limited by visible-light absorption capacity and charge separation kinetics. Herein, we report an interface-engineered 2D-C₃N₄/NiFe layered double hydroxide (CN/LDH) heterostructure that shows highly enhanced photocatalytic hydrogen evolution reaction (HER) rate with excellent long-term stability. The morphology and band gap structure of NiFe-LDH are precisely regulated by employing NH₄F as a structure-directing agent, which enables a fine interfacial tuning via coupling with 2D-C₃N₄. The formation of a type II interface in CN/LDH enlarges the active surface area and promotes the charge separation efficiency, leading to an HER rate of 3087 μmol g^–1 h^–1, which is 14 times higher than that of 2D-C₃N₄. This study highlights a rational interface engineering strategy for the formation of a heterostructure with a proper hole transport co-catalyst for designing effective water-splitting photocatalysts.

Silicon-based anode fabrication with nanoscale structuration improves the energy density and life cycle of Li-ion batteries. As-synthesized silicon (Si) nanowires (NWs) or nanoparticles (NPs) directly on the current collector represent a credible alternative to conventional graphite anodes. However, the operating potentials of these electrodes are below the electrochemical stability window of all electrolytes used in commercial Li-ion systems. During the first charging phase of the cell, partial decomposition of the electrolyte takes place, which leads to the formation of a layer at the surface of the electrode, called solid electrolyte interphase (SEI). A stable and continuous SEI layer formation is a critical factor to achieve reliable lifetime stability of the battery. Once formed, the SEI acts as a passivation layer that minimizes further degradation of the electrolyte during cycling, while allowing lithium-ion diffusion with their subsequent insertion into the active material and ensuring reversible operation of the electrode. However, one of the major issues requiring deeper investigation is the assessment of the morphological extension of the SEI layer into the active material, which is one of the main parameters affecting the anode performances. In the present study, we use electron tomography with a low electron dose to retrieve three-dimensional information on the SEI layer formation and its stability around SiNWs and SiNPs. The possible mechanisms of SEI evolution could be inferred from the interpretation and analysis of the reconstructed volumes. Significant volume variations in the SiNW and an inhomogeneous distribution of the SEI layer around the NWs are observed during cycling and provide insights into the potential mechanism leading to the generally reported SiNW anode capacity fading. By contrast, analysis of the reconstructed SiNPs’ volume for a sample undergoing one lithiation–delithiation cycle shows that the SEI remains homogeneously distributed around the NPs that retain their spherical morphology and points to the potential benefit of such nanoscale Si anode materials to improve their cycling lifetime.

Surface modification engineering is an effective method to improve the crystallinity and passivate the perovskite interface and grain boundary, which can improve the power conversion efficiency (PCE) and stability of perovskite solar cells (PSCs). The typical interface modification method is usually introduced at the interface of the perovskite/hole transport layer (HTL) or perovskite/electron transport layer (ETL) through coordination of the groups in the material with the perovskite. In this work, the n-type semiconductor bathocuproine (BCP) including the pyridine nitrogen bond was modified at the interfaces of perovskite/HTL or perovskite/ETL to improve perovskite crystallinity and interface contact properties. The better crystallinity and superior interface contact properties are obtained using BCP unilateral modification, which obviously increases the PCEs of PSCs. The BCP bilateral modification at both perovskite/ETL and perovskite/HTL interfaces can further improve the crystallinity with fewer defects and superior contact properties, which show the largest V_oc (1.14 V) and fill factors (FF 77.1%) compared to PSCs with BCP unilateral modification. PSCs with BCP bilateral modification obtained 20.6% PCEs, which is greatly higher than that (17.5%) of the original PSCs. The stability of PSCs with BCP bilateral modification can be greatly improved due to the better crystal quality and hydrophobic property of the interfaces. The results demonstrated that the n-type BCP material can efficiently modify both perovskite/HTL and perovskite/ETL interfaces beyond its semiconductor type, which can greatly improve the PCEs and stability of PSCs because BCP modification can passivate interfaces, improve interface contact and hydrophobic properties, promote crystallinity of the perovskite layer with fewer defects, and block carrier recombination at both interfaces.

Zinc–iodine (Zn/I₂) batteries are recognized as a kind of leading candidate for large-scale energy storage systems, owing to the high-capacity dissolution–deposition reactions on both electrodes. Nevertheless, the lifespan of Zn/I₂ batteries is severely limited by the uncontrolled shuttling of triiodide ions (I₃^–) and unfavorable side reactions on Zn anodes. Herein, an alginate-based polyanionic hydrogel electrolyte is designed and synthesized by ion exchange and Zn²⁺-induced cross-linking. The immobile, negatively charged polyanionic chains on the hydrogel skeleton effectively block I₃^– from shuttling, while simultaneously transporting cations that are indispensable for battery chemistry. Moreover, this hydrogel can also enhance the cycling durability of Zn anodes by alleviating Zn’s dendritic growth and corrosion reactions, due to the homogenized Zn²⁺ flux and reduced interfacial contact between free water and metallic Zn. Consequently, this alginate-based hydrogel electrolyte enables stable Zn plating/stripping for over 600 h at 2 mA cm^–2 and 2 mAh cm^–2 (corresponding to 10% depth of discharge). Serving as an electrolyte for Zn/I₂ full batteries, this hydrogel helps the battery to achieve a high capacity of 183.4 mAh g^–1 (capacity retention = 97.6%) after even 200 cycles at 0.2 A g^–1, 77.4% higher than that of the traditional ZnSO₄ aqueous counterpart (residual capacity = 41.5 mAh g^–1). This work indicates the promising potential of electrolyte design on the performance improvement of aqueous Zn/I₂ batteries.

Achieving a high-energy charge-transfer state (E_CT) and concurrently reduced energy loss is of vital importance in boosting the open-circuit voltage (V_oc) of organic solar cells (OSCs), but it is difficult to realize. We report herein a novel design tactic to achieve this goal by incorporating a three-dimensional (3D) shape-persistent norbornenyl group into the terminals of acceptor–donor–acceptor-type nonfullerene acceptors (NFAs). Compared with ITIC-based OSCs, norbornenyl-fused 1,1-dicyanomethylene-3-indanone (CBIC) terminals endow IDTT-CBIC-based OSCs with simultaneously higher E_CT and lower radiative and non-radiative voltage loss, hence enhancing V_oc by 90 mV. CBIC also improves the miscibility and modulates the molecular packing structures for efficient charge carrier transport and a better short-circuit current density in IDTT-CBIC-based OSCs. Consequently, the power conversion efficiency is improved by 22%, compared to that of the OSC based on ITIC. Furthermore, the effectiveness of the use of CBIC as the terminals is observed using different electron-donating cores. The utilization of the 3D shape-persistent building blocks represents a breakthrough in the design strategies for terminal groups toward efficient NFA-based OSCs with high V_oc.

With the rapid development in wearable electronics, self-powered devices have recently attracted tremendous attention to overcome the restriction of conventional power sources. In this regard, a simple, scalable, and one-pot electrospinning fabrication technique was utilized to construct an all-fiber-structured triboelectric nanogenerator (TENG). Ethyl cellulose was co-electrospun with polyamide 6 to serve as the triboelectric positive material, and a kind of strongly electronegative conductive material of MXene sheet was innovatively incorporated into poly(vinylidene fluoride) nanofiber to act as a triboelectric negative material. The assembled all-fiber TENG exhibited excellent durability and stability, as well as excellent output performance, which reached a peak power density of 290 mW/m² at a load resistance of 100 MΩ. More importantly, the TENG was capable of harvesting energy to power various light-emitting diodes (LEDs) and monitoring human movements as a self-powered sensor, providing a promising application prospect in wearable electronics.

A three-dimensional (3D) printing method has been developed for preparing a lithium anode base on 3D-structured copper mesh current collectors. Through in situ observations and computer simulations, the deposition behavior and mechanism of lithium ions in the 3D copper mesh current collector are clarified. Benefiting from the characteristics that the large pores can transport electrolyte and provide space for dendrite growth, and the small holes guide the deposition of dendrites, the 3D Cu mesh anode exhibits excellent deposition and stripping capability (50 mAh cm^–2), high-rate capability (50 mA cm^–2), and a long-term stable cycle (1000 h). A full lithium battery with a LiFePO₄ cathode based on this anode exhibits a good cycle life. Moreover, a 3D fully printed lithium–sulfur battery with a 3D printed high-load sulfur cathode can easily charge mobile phones and light up 51 LED indicators, which indicates the great potential for the practicability of lithium-metal batteries with the characteristic of high energy densities. Most importantly, this unique and simple strategy is also able to solve the dendrite problem of other secondary metal batteries. Furthermore, this method has great potential in the continuous mass production of electrodes.

A bimetallic catalytic membrane microreactor (CMMR) with bimetallic nanoparticles in membrane pores has been fabricated via flowing synthesis. The bimetallic nanoparticle is successfully immobilized in membrane pores along its thickness direction. Enhanced synergistic catalysis can be expected in this CMMR. As a concept-of-proof, Cu–Ag core–shell nanoparticles have been fabricated and immobilized in membrane pores for p-nitrophenol (p-NP) hydrogenation. Transmission electron microscopy (TEM) for the characterization of the bimetallic core–shell nanostructure and X-ray photoelectron spectroscopy (XPS) for the characterization of the electron transfer behavior between Cu–Ag bimetal have been performed. The Ag shell on the core of Cu can improve the utilization of Ag atoms, and electron transfer between bimetallic components can promote the formation of high electron density active sites as well as active hydrogen with strong reducing properties on the Ag surface. The dispersed membrane pore can prevent nanoparticle aggregation, and the contact between the reaction fluid and catalyst is enhanced. The enhanced mass transfer can be achieved by the plug-flow mode during the process of hydrogenation catalysis. The p-NP conversion rate being over 95% can be obtained under the condition of a membrane flux of 1.59 mL·cm^–2·min^–1. This Cu–Ag/PES CMMR has good stability and has a potential application in industry.

Oxygen vacancies play a positive role in optimizing the physical and chemical properties of metal oxides. In this work, we demonstrated oxygen vacancy-promoted enhancement of Li-ion diffusion kinetics in Li₂GeO₃ nanoparticle-encapsulated carbon nanofibers (denoted as Li₂GeO_3–x/C) and accordingly boosted lithium storage. The introduction of the oxygen vacancies in Li₂GeO_3–x/C can enhance electronic conductivity and evidently decrease activation energy of Li-ion transport, thus resulting in evidently accelerated Li-ion diffusion kinetics during the lithiation/delithiation process. Thus, the Li₂GeO_3–x/C nanofibers exhibit an exceptionally large discharge capacity of 1460.5 mA h g^–1 at 0.1 A g^–1, high initial Coulombic efficiency of 81.3%, and excellent rate capability. This facile and efficient strategy could provide a reference for injecting the oxygen vacancies into other metal oxides for high-performance anode materials.

Photoassisted electrocatalytic (P-EC) water splitting for H₂ production has received much attention. Here, we report a metal-free bifunctional photoassisted catalyst of a polyaniline/carbon dots (PANI/CDs) composite for overall water splitting. In a neutral electrolyte, under visible light, the overpotentials of the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) for PANI/CDs/NF are reduced by 150 and 65 mV to reach the current densities of 30 and 20 mA cm^–2, respectively. In a full water-splitting cell, under visible light, the current density is 13.27 mA cm^–2 at 2.0 V, which increases by 62.8% compared with that under the dark conditions (8.15 mA cm^–2). The in situ transient photovoltage (TPV) tests were used to study the light-induced effects on half-reactions of water splitting, as well as the charge-transfer kinetic characteristics at the catalyst interface.

Organic–inorganic lead halide perovskite solar cells (PSCs) are highly efficient, flexible, lightweight, and even tolerant to radiation, such as protons, electron beams (EB), and γ-rays, all of which makes them plausible candidates for use in space satellites and spacecrafts. However, the mechanisms of radiation damage of each component of PSC [an organic hole transport material (HTM), a perovskite layer, and an electron transport material (ETM)] are not yet fully understood. Herein, we investigated the EB irradiation effect (100 keV, up to 2.5 × 10¹⁵ cm^–2) on binary-mixed A site cations and halide perovskite (MA_0.13FA_0.87PbI_2.61Br_0.39, MA:methylammonium cation and FA:formaminidium cation), a molecular HTM of doped SpiroOMeTAD, and an inorganic ETM of mesoporous TiO₂. Despite the decreased power conversion efficiency of PSCs upon EB exposure, the photoconductivities of the perovskite, HTM, and ETM layers remained intact. In contrast, significant dedoping of HTM was observed, as confirmed by steady-state conductivity, photoabsorption, and X-ray photoelectron spectroscopy measurements. Notably, this damage could be healed by exposure to short-wavelength light, leading to a partial recovery of the PSC efficiency. Our work exemplifies the robustness of perovskite against EB and the degradation mechanism of the overall PSC performance.

Sr_0.7Bi_0.2TiO₃ (SBT) is a promising pulse energy storage material due to minor hysteresis, but its low maximum polarization (P_max) is bad for energy storage. K⁺–Bi³⁺ defect pairs were introduced into the A-site of SBT to obtain Sr_0.35Bi_0.35K_0.25TiO₃ (SBKT) with larger P_max. Through first-principles calculations, we determined that the introduction of defect pairs destroys the paraelectric order phase and increases local polarization, resulting in more and larger polar nanoregion (PNR) formation. On this basis, doping NaNbO₃ (NN) in A- and B-sites of SBKT increases the cationic disorder and ferroelectric destabilization, further destroying the long-range order structure and forming more PNRs with smaller sizes. This enhances relaxation and decreases remnant polarization, and the broadened dielectric peak enables 0.85SBKT–0.15NN to meet the X7R specification. Furthermore, the decreased grain size and oxygen vacancy, increased thermal conductivity, and weakened local electric field (simulated by COMSOL) increase the dielectric breakdown strength (BDS). As a result, 0.95SBKT–0.05NN exhibits a high energy storage density (W) of 2.45 J/cm³ with a high efficiency of 93.1%, a high pulsed discharge energy density of 2.1 J/cm³, and a high power density of 54.1 MW/cm³ at 220 kV/cm. The energy storage properties show excellent stability of temperature (−55 to 150 °C), frequency (10–500 Hz), and cycling (10⁵ cycles). Notably, for the pulse charge–discharge properties, 0.95SBKT–0.05NN shows great fatigue resistance during 10⁵ cycles under 25 and 150 °C, accompanied by excellent thermal stability. Moreover, the BDS and P_max of 0.95SBKT–0.05NN sintered in O₂ further enhance. A higher W of 2.92 J/cm³ with a high efficiency of 89% at 250 kV/cm is achieved. Therefore, 0.95SBKT–0.05NN shows great application potential for pulse energy storage. In this work, we provide a novel strategy and systematic in-depth study for improving the energy storage properties of SBT.

Strong metal–support interaction is crucial to the stability of catalysts in heterogeneous catalysis. However, reports on boosting interfacial electron transfer between metal and support via defect induction for enhanced metal–support interaction are limited. In this work, ultrathin reducible ZnTi-layered double hydroxide (LDH) nanosheets with rich oxygen defects were synthesized to stabilize Pd clusters, and the rich oxygen defects promoted Pd cluster bonding with Zn and Ti atoms in supports, thereby forming a metal–metal bond. Electron spin resonance (ESR), X-ray absorption fine spectra (XAFS), and density functional theory (DFT) calculations demonstrate remarkable interfacial electron transfer (0.62 e). The Pd/ZnTi-LDH catalyst shows superior catalytic stability for CO direct esterification to dimethyl oxalate. By contrast, the nonreducible Pd/ZnAl-LDH catalyst with a few oxygen defects shows minimal interfacial electron transfer (0.08 e), which leads to relatively poor catalytic stability. This work provides a deep insight into promoting the stability of catalysts by boosting interfacial electron transfer via defect induction.

As the use of pesticides in agriculture is increasing at an alarming rate, food contamination by pesticide residues is becoming a huge global problem. It is essential to develop a sensitive and user-friendly sensor device to quantify trace levels of pesticide and herbicide residues in food samples. Herein, we report an electrocatalyst made up of yttrium iron garnet (Y₃Fe₅O₁₂; YIG) and graphitic carbon nitride (GCN) to attain picomolar-level detection sensitivity for mesotrione (MTO), which is a widely used herbicide in agriculture. First, YIG was prepared by a hydrothermal route; then, it was loaded on GCN sheets via a calcination method. The surface structures, composition, crystallinity, and interfacial and electrocatalytic properties of the YIG and YIG/GCN were analyzed. As the YIG/GCN displayed better surface and catalytic properties than YIG, YIG/GCN was modified on a screen-printed carbon electrode to fabricate a sensor for MTO. The YIG/GCN-modified electrode displayed a detection limit of 950 pM for MTO. The method was demonstrated in (spiked) fruits and vegetables. Then, the modified electrode was integrated with a miniaturized potentiostat called KAUSTat, which can be operated wirelessly by a smartphone. A first smartphone-based portable sensor was demonstrated for MTO that is suitable for use in nonlaboratory settings.

The encapsulation of an organic dye, 10-phenylphenothiazine (PTH), in the inner cavity of single-walled carbon nanotubes (SWNTs) as a breaking heterogenization strategy is presented. The PTH@oSWNT material was microscopically and spectroscopically characterized, showing intense photoemission when illuminated with visible light at the nanoscale. Thus, PTH@oSWNT was employed as a heterogeneous photocatalyst in single electron transfer dehalogenation reactions under visible light irradiation. The material showed an enhanced photocatalytic activity, achieving turnover numbers as high as 3200, with complete recyclability and stability for more than eight cycles. Computational calculations confirm that electronic communication between both partners is established because, upon illumination, an electron of the excited PTH is transferred from the π system of the molecule to the delocalized π-cloud of the SWNT, thus justifying the enhanced photocatalytic activity.

Low-cost transition-metal oxide is regarded as a promising electrocatalyst family for an oxygen evolution reaction (OER). The classic design principle for an oxide electrocatalyst believes that point defect engineering, such as oxygen vacancies (V_O^..) or heteroatom doping, offers the opportunities to manipulate the electronic structure of material toward optimal OER activity. Oppositely, in this work, we discover a counterintuitive phenomenon that both V_O^.. and an aliovalent dopant (i.e., proton (H⁺)) in perovskite nickelate (i.e., NdNiO₃ (NNO)) have a considerably detrimental effect on intrinsic OER performance. Detailed characterizations unveil that the introduction of these point defects leads to a decrease in the oxidative state of Ni and weakens Ni–O orbital hybridization, which triggers the local electron–electron correlation and a more insulating state. Evidenced by first-principles calculation using the density functional theory (DFT) method, the OER on nickelate electrocatalysts follows the lattice oxygen mechanism (LOM). The incorporation of point defect increases the energy barrier of transformation from OO*(V_O) to OH*(V_O) intermediates, which is regarded as the rate-determining step (RDS). This work offers a new and significant perspective of the role that lattice defects play in the OER process.

As the demand of fossil fuels continues to expand, hydrogen energy is considered a promising alternative energy. In this work, the NiTiO₃–CuI-GD ternary system was successfully constructed based on morphology modulation and energy band structure design. First, the one-pot method was used to cleverly embed the cubes CuI in the stacked graphdiyne (GD) to prepare the hybrid CuI-GD, and CuI-GD was anchored on the surface of NiTiO₃ by simple physical stirring. The unique spatial arrangement of the composite catalyst was utilized to improve the hydrogen production activity under light. Second, to combine various characterization tools and energy band structures, we proposed an step-scheme (S-scheme) heterojunction photocatalytic reaction mechanism, among them, the tubular NiTiO₃ formed by the self-assembled of nanoparticles provided sufficient sites for the anchoring of CuI-GD, and the thin layer GD acted as an electron acceptor to capture a large number of electrons with the help of the conjugated carbon network; cubes CuI could consume holes in the reaction system; the loading of CuI-GD greatly improved the oxidation and reduction ability of the whole catalytic system. The S-scheme heterojunction accelerated the transfer of carriers and improved the separation efficiency. The experiment provides a new insight into the construction of an efficient and eco-friendly multicatalytic system.

Triazole-based g-C₃N₅, a potential catalyst, has received little attention over the years. We prepared phosphorus-doped g-C₃N₅ with one triazole and two triazine units for the first time to investigate its photoelectrochemical (PEC) and photocatalytic properties. The doping states and crystalline structures of the samples were determined using X-ray techniques, namely, X-ray diffraction, X-ray photoelectron spectroscopy, and X-ray absorption fine structure analysis. Our results suggested that the phosphorus was substituted into carbon sites form P–N/P═N bonds with four coordination, which contribute P 2p level donor states in the band gap to enhance light absorption and reduce charge separation. Therefore, P-doped g-C₃N₅ exhibited higher PEC current density and better photocatalytic efficiency toward the degradation of rhodamine B dye or tetracycline under light irradiation compared to the undoped g-C₃N₅ sample. However, excess phosphorus doping resulted in the formation of impurities and disrupted the triazine and triazole units, reducing the PEC and photocatalytic efficiency. In summary, P-doped g-C₃N₅ was successfully prepared in the present study and represents a promising, facile, and effective catalyst for energy applications and environmental remediation.

Microsized SiO_x has been vigorously investigated as an advanced anode material for next-generation lithium-ion batteries. However, its practical application is seriously hampered by its huge volume variation during the repeated (de)lithiation process, which destroys the microparticle structure and results in rapid capacity fading. Herein, we propose the usage of trans-difluoroethylene carbonate (DFEC) as an electrolyte additive to maintain the structural integrity of microsized SiO_x with a uniform carbon layer (SiO_x@C). Compared with ethylene carbonate and fluoroethylene carbonate, DFEC has lower lowest unoccupied molecular orbital energy and higher reduction potential, which is easily reduced and promotes the in situ formation of a more stable LiF-rich solid electrolyte interphase (SEI) on the surface of anode materials. The LiF-rich SEI exhibits enhanced mechanical rigidity and ionic conductivity, thus enabling the microsized SiO_x@C anodes’ excellent lithium storage stability and high average Coulombic efficiency.

Ni-rich layered cathodes suffer detrimental structural changes due to irreversible phase transformation (IPT). Precisely surface structural reconstruction through foreign element doping is a potential method to alleviate IPT propagation. The structure of surface reconstructed layer is greatly determined by the foreign element content and species. Herein, small doses of Ti and Al were co-substituted in LiNi_0.92Co_0.08O₂ to synergistically regulate the surface reductive Ni distribution, consequently constructing thin rock salt phase at the particle surface. This homogeneous rock salt phase combined with the strong Ti–O and Al–O bonds generated a reversible H2–H3 phase transition and further eliminated IPT propagation. Moreover, the suppressed IPT propagation converted the two-phase (H2 and H3) coexistence to a quasi-single-phase transition. This eliminated the strong internal strains caused by a significant lattice mismatch. The Ti and Al co-substituted LiNi_0.92Co_0.08O₂ exhibited outstanding capacity retention and excellent structural stability. Similar improvements were observed with W or Zr and Al cosubstitution in Ni-rich layered cathodes. This study proposes a universal method for comprehensive improvement of structural stability based on the synergistic effect of dual-element cosubstitution in Ni-rich layered oxide cathodes, which is being explored for production of high-cycle-stability lithium-ion batteries.

Bismuth telluride alloys have dominated the industrial application of thermoelectric cooling, but the relatively poor mechanical performance of commercial zone-melting material seriously limits the device integration and stability. Here, we exhibit synergistically enhanced thermoelectric and mechanical performances of sintered Bi_0.48Sb_1.52Te₃–AgSbSe₂ composites. It is found that the increased hole concentration improves the S²σ to 40 μW cm^–1 K^–2 at room temperature, and the emerged various defects effectively suppress the κ_l to 0.57 W m^–1 K^–1 at 350 K. All effects harvest a highest ZT = 1.2 at 350 K along with an average ZT = 1.0 between 300–500 K in the x = 0.2 sample. Notably, AgSbSe₂ addition not only optimizes the thermoelectric properties, but also enhances the mechanical performance with a Vickers hardness of 0.75 GPa. Furthermore, the isotropy of thermoelectric properties is also observably promoted by solid-phase reaction combined with high-energy ball milling and hot pressing. Our study reveals a viable strategy to improve the comprehensive performance of sintered bismuth telluride materials.

Solar steam generation is an efficient way of harvesting solar energy for water purification. Developing a versatile solar absorber with salt resistance and the capability to purify an oil-in-water emulsion is a grand challenge. Herein, a polypropylene (PP) nonwoven fabric-based photothermal absorber is fabricated by the combination of carbon nanotubes (CNTs), polypyrrole (PPy), and a fluorinated hydrophobic coating in a layer-by-layer approach. The specially designed architecture displays a hierarchical microstructure and Janus wetting properties, facilitating solar absorption and heat generation on the evaporation surface, and can effectively prevent salt crystallization. The water layer formed on the superhydrophilic/underwater superoleophobic bottom surface could repel oil droplets and form a channel to advect concentrated salt back into bulk water, which enabled high purity separation of an oil-in-water emulsion and continuous desalinization of seawater without the reduction of the evaporation rate. As a result, the solar absorber can achieve a remarkable evaporation rate of 1.61 kg m^–2 h^–1 and an energy efficiency of 91.2% under 1 sun irradiation and shows extraordinary performance in the purification of contaminated wastewater (over 99.8% purity). The strategy proposed provides a pathway for developing versatile high-performance solar absorbers for the sustainable treatment of saline water, wastewater, and oil-containing water.

The size effects of metal catalysts have been widely investigated to optimize their catalytic activity and selectivity. However, the size-controllable synthesis of uniform supported metal nanoparticles without surfactants and/or additives remains a great challenge. Herein, we developed a green, surfactant-free, and universal strategy to tailor the sizes of uniform Pd nanoparticles on metal oxides by an electroless chemical deposition method via defect engineering of supports. The nucleation and growth mechanism suggest a strong electrostatic interaction between the Pd precursor and low-defective CeO₂ and a weak reducing capacity for low-defective CeO₂, resulting in small Pd nanoparticles. Conversely, large Pd nanoparticles were formed on a highly defective CeO₂ surface. Combined with various ex situ and in situ characterizations, a higher intrinsic activity of Pd for the CO₂-to-CO hydrogenation was found on large Pd nanoparticles with higher electron density owing to their stronger H₂ dissociation ability and H-spillover effects, as well as the larger number of oxygen vacancies generated in situ for CO₂ activation under hydrogenation conditions.

The development of transition metal-based heterogeneous catalysts for economical and efficient synthesis of secondary imines remains both desirable and challenging. Herein, for the first time, we present two kinds of Rh nanoparticle anchored uniform spherical COF heterogeneous catalysts with well-defined crystalline structures for the effective one-pot tandem reductive amination of aldehydes on a gram scale. This reaction is carried out using ammonia as a nitrogen source and hydrogen gas as the source of hydrogen, which is not only an atom-economical but also an environmentally friendly process for the selective production of secondary imines. In particular, in the presence of the better-designed Rh nanoparticles anchored COF2 catalyst, the starting material aldehydes could be fully converted (99% conversion), and 95% selectivity of N-benzylidene(phenyl)methanamine is obtained under mild reaction conditions (2 MPa of H₂ and 90 °C). Additionally, the Rh/COF2 catalyst is also applied to a variety of substituted aromatic aldehyde compounds, manifesting good yields in corresponding secondary imines. This work not only expands the COF family but also offers economical and effective access to acquire various aromatic amine targets, especially secondary imines.

Carbon capture from industrial effluents such as flue gas or natural gas mixture (cf. landfill gas), the primary sources of CO₂ emission, greatly aids in balancing the environmental carbon cycle. In this context, the most energy-efficient physisorptive CO₂ separation process can benefit immensely from improved porous sorbents. Metal organic frameworks (MOFs), especially the ultramicroporous MOFs, built from readily available small and rigid ligands, are highly promising because of their high selectivity (CO₂/N₂) and easy scalability. Here, we report two new ultramicroporous Co-adeninato isophthalate MOFs. They concomitantly carry basic functional groups (−NH₂) and Lewis acidic sites (coordinatively unsaturated Co centers). They show good CO₂ capacity (3.3 mmol/g at 303 K and 1 bar) along with high CO₂/N₂ (∼600 at 313 K and 1 bar and ∼340 at 303 K and 1 bar) selectivity, working capacity, and smooth diffusion kinetics (D_c = 7.5 × 10^–9 m² s^–1). The MOFs exhibit good CO₂/N₂ kinetic separation under both dry and wet conditions with a smooth breakthrough profile. Despite their well-defined CO₂ adsorption sites, these MOFs exhibit only a moderately strong interaction with CO₂ as evidenced from their HOA values. This counterintuitive observation is ubiquitous among many MOFs adorned with strong CO₂ adsorption sites. To gain insights, we have identified the binding sites for CO₂ using simulation and MD studies. The radial distribution function analysis reveals that despite the amine and bare-metal sites, the pore size and the pore structure determine the positions for the CO₂ molecules. The most favorable sites become the confined spaces lined by aromatic rings. A plausible explanation for the lack of strong adsorption in these MOFs is premised from these collective studies, which could aid in the future design of superior CO₂ sorbents.

Li–air batteries are a promising alternative to Li-ion batteries as they theoretically provide the highest possible specific energy density. Mainly, Li₂O₂ (lithium peroxide) and to a lesser extent, Li₂O (lithium oxide) are assumed to be the discharge products of these batteries formed with the soluble LiO₂ (lithium superoxide) considered to be an intermediate product. Bulk Li₂O₂ is an electronic insulator, and the precipitation of this compound on the cathode is thought to be the main limiting factor in achieving high capacities in lithium–oxygen cells. For the most promising electrolytes including solvents with high donor numbers, microscopy observations frequently reveal crystallite morphologies of Li₂O₂ compounds, rather than uniform layers covering the electrode surface. The precise morphologies of Li₂O and Li₂O₂ particles, and their effect and their extent of contact with the electrode, which may all affect the capacity and rechargeability, however, remain largely undetermined. Here, we address the stability of various Li₂O and Li₂O₂ surfaces and consequently, their crystallite morphologies using density functional theory calculations and ab initio thermodynamics. In contrast to previous studies, we also consider high-index surface terminations, which exhibit surprisingly low surface energies. We carefully analyze the reasons for the stability of these high-index surfaces, which also prominently influence the equilibrium shape of the particles, at least for Li₂O₂, and discuss the consequences for the observed morphology of the reaction products.

A novel electrolyte system with an excellent low-temperature performance for lithium-ion batteries (LIBs) has been developed and studied. It was discovered for the first time, in this work, that when isoxazole (IZ) was used as the main solvent, the ionic conductivity of the electrolyte for LIBs is more than doubled in a temperature range between −20 and 20 °C compared to the baseline electrolyte using ethylene carbonate–ethyl methyl carbonate as solvents. To solve the problem of solvent co-intercalation into the graphite anode and/or electrolyte decomposition, the lithium difluoro(oxalato)borate (LiDFOB) salt and fluoroethylene carbonate (FEC) additive were used to form a stable solid electrolyte interphase on the surface of the graphite anode. Benefitting from the high ionic conductivity at low temperature, cells using a new electrolyte with 1 M LiDFOB in FEC/IZ (1:10, vol %) solvents demonstrated a very high reversible capacity of 187.5 mAh g^–1 at −20 °C, while the baseline electrolyte only delivered a reversible capacity of 23.1 mAh g^–1.

Sulfurized polyacrylonitrile (SPAN) is an attractive cathode candidate for the advanced lithium–sulfur (Li–S) batteries owing to its outstanding cyclic stability. Nevertheless, SPAN suffers from inadequate initial Coulombic efficiency (CE) induced by the sluggish reaction kinetics, which is primarily ascribed to the low Li-ion diffusivity and high electronic resistivity of the Li₂S product. In this work, an optimal trace amount of soluble lithium polysulfide of Li₂S₈ is introduced as a redox mediator for a freestanding fibrous SPAN cathode to enhance the reversible oxidation efficiency of Li₂S. During the delithiation process, the chemical interactions between Li₂S and Li₂S₈ additive facilitate the electrochemical oxidation of Li₂S, resulting in the transformation of not only C–S/S–S bonds in SPAN but also elemental sulfur. Benefiting from the synergistic effect of the two competing reactions, a high initial CE of 82.9% could be achieved at a current density of 200 mA g^–1. Moreover, a superior capacity retention along with a high capacity of 1170 mAh g^–1 up to the 400th cycle is available at 1000 mA g^–1. The study offers a feasible approach for Li–S batteries toward the practical applications of SPAN.

High-performance triiodide reduction reaction (IRR) catalysts in dye-sensitized solar cells (DSSCs) and hydrogen evolution reaction (HER) catalysts in electrochemical water splitting are extremely compelling for renewable energy conversion and storage. The best IRR and HER catalysts generally rely on the use of noble metal platinum (Pt), which suffers obstacles in real-world implementation. The rational design of efficient bifunctional IRR and HER catalysts based on inexpensive and earth-abundant elements to replace scarce Pt could enable low-cost photoelectric conversion and hydrogen production but is challenging and rarely reported. Herein, we present a bifunctional NiFeCoW@NC hybrid with the unique architecture of WC loaded on the in situ formed carbon nanotubes embedded with Co-doped FeNi₃ nanoparticles based on the anisotropic integration design principle, which operates efficiently for DSSCs and hydrogen evolution. The assembled DSSCs using the designed multimetal-based NiFeCoW@NC counter electrode delivered a high power conversion efficiency of 6.92% and long-term stability superior to bimetal-based NiFe@NC, CoW@NC, and Pt counterparts. It also exhibited eminent hydrogen evolution performance with a low overpotential of 127.8 mV to drive a 10 mA cm^–2 current density, a Tafel slope of 60.4 mV dec^–1, and satisfactory durable stability in 0.5 M H₂SO₄. This work provides a design principle for low-cost and highly active bifunctional catalysts to replace Pt for DSSCs and hydrogen evolution.

Gel polymer electrolyte (GPE) is one of the most promising alternatives to solve the bottlenecks of nonaqueous liquid electrolytes such as decomposition, safety hazards, and growth of dendrites. In this work, three novel methyl phosphonate-based crosslinking gel terpolymer electrolytes with different comonomers are designed and prepared by in situ radical polymerization. The gel polymer electrolytes have excellent thermal stability, wide electrochemical windows (≥4.9 V), and high ionic conductivities (±3 mS cm^–1), and may be used as less-flammable electrolytes for sodium-ion batteries. ³¹P NMR spectra, Arrhenius plot, and density functional theory (DFT) calculations confirm that multifunctional phosphonate structural units promote the dissociation of NaClO₄ and help to transport the sodium ions freely in the polymer framework. X-ray photoelectron spectroscopy (XPS) results show that the gel polymer electrolytes have the capability of inhibiting liquid electrolyte decomposition and the formation of the stable solid electrolyte interphase (SEI) film. The Na₃V₂(PO₄)₃/GPE/Na cells exhibit better ultralong cycling stability and enhanced temperature performance than those of liquid cells. Strikingly, GPE1 has the best comprehensive electrochemical performance, especially the rate performance and long-term cycling stability with a capacity retention ratio of 82.6% after 3500 cycles, which indicates that different comonomers have obvious effects on the performance. Therefore, the full cell of SnS₂/GPE1/Na₃V₂(PO₄)₃ is evaluated and delivers good cycling stability of 500 cycles, holding a great prospect for the design and production of phosphorus-containing electrolytes for safer sodium-ion batteries.

In this work, several carbon-decorated Na₃V₂(PO₄)₃ materials (NVP@C-750/800/850) are successfully fabricated using a sol–gel approach and subsequent heat treatment. When NVP@C-800 is used as a cathode, it shows an ultralong cycle life (2000 cycles) at a high rate of 10C, which is superior to the other two electrodes and those of reported NVP@C cathodes in the literature. The excellent results of NVP@C-800 are attributed to its nanostructure and the well-defined conductive carbon layer. The symmetric sodium (Na)-ion battery (SIB) with NVP@C-800 as both a cathode and an anode shows a high capacity at 40 mA g^–1 with a voltage plateau of about 1.79 V and energy density of 113 W h kg^–1, revealing that NVP@C is of great application prospect.

Integration of novel bio-/nanostructures as effective sensing platforms is still of great significance for robust and rapid analysis. Herein, a novel metal–organic framework-derived NiCo₂O₄ was synthesized via a feasible templating method. Significantly, redox couples of both Ni³⁺/Ni²⁺ and Co³⁺/Co²⁺ provided richer oxidation–reduction reactions, thereby leading to an enhanced catalytic activity. Furthermore, NiCo₂O₄ as an enzyme mimic with peroxidase-like activity and oxidase-like activity could oxidize colorless thylbenzidine (TMB) to blue oxTMB in the absence of H₂O₂. Thus, a sensitive chromogenic sensing platform for detecting Fe²⁺, thiourea, cysteine (Cys), and epigallocatechin-3-gallate (EGCG) was proposed. The colorimetric detection methods exhibited great features of low limit of detection (LOD) and broad linear range. Owing to the complexation reaction, the chromogenic sensing system of TMB + NiCo₂O₄ + Cys achieved effective detection of Cu²⁺ and Mn²⁺ with the LODs of 0.0022 and 0.0181 mM, respectively. Developed detection methods with wide linear ranges of 0.008–0.1 mM for Cu²⁺ and 0.08–1 mM for Mn²⁺ had excellent practical potential. Similarly, the reaction system of TMB + NiCo₂O₄ + EGCG could achieve the colorimetric detection of Cu²⁺ and Fe³⁺. The great chromogenic sensing performance for detecting Cu²⁺ and Fe³⁺ with a broad linear range and a low LOD could be also realized.

To fulfill the increasing demand for radiofrequency (RF) wireless communication capacity for epidermal electronics, stretchable integrated circuits (ICs) in the gigahertz (GHz) range are desirable. Lumped RF inductors, as a key component in RFICs, typically dominate a large portion of the circuit/chip area and therefore make such inductors mechanically stretchable is critical for GHz-frequency stretchable RFICs. Most of the reported stretchable inductors operate in the MHz frequency range. The only GHz stretchable inductor shows a quality factor of about 2, limiting its potential RF applications. Here, stretchable inductors with a high quality factor of Q > 12.6 and resonance operation frequency of f_res > 11.6 GHz are demonstrated by combining microspirals with stretchable structures, overcoming all of the shortcomings of previous demonstrations. Furthermore, a stretchable 1.5–2.6 GHz filter with a peak insertion loss of −2.3 dB at 1.8 GHz is developed, showing negligible performance changes under stretching or on the skin to demonstrate the utility in practical wireless applications like GSM and Bluetooth (2.45 GHz) bands. The demonstrations can facilitate multiple GHz epidermal RFICs in the future.

Chalcogenide-based quantum dots are useful for the application of memory-switching devices because of the control in the trap states in the materials. The control in the trap states can be achieved using a hot-injection colloidal synthesis method that produces temperature-dependent size-variable quantum dots. In addition to this, formation of a nanoscale heterostructure with an insulating material adds to the charge-trapped switching mechanism. Here, we have shown that the colloidal monodispersed CdSe quantum dots and poly(4-vinylpyridine) (PVP) formed a nanoscale heterostructure between themselves when taken in a suitable ratio to fabricate a device. This heterostructure helps realize memory-switching in the device with a maximum on–off current ratio of 10⁵. The switching in the device is mainly due to the trap states in the CdSe quantum dots. The conduction in the off state is due to thermal charge injection and space charge injection conduction and in the on state, due to the Ohmic conduction mechanism.

Negative differential resistance (NDR) can be applied to various devices such as reflection amplifiers, relaxation oscillators, and neuromorphic devices. However, the development of NDR photodetectors with uniformity, stability, and reproducibility for use in practical applications is still lacking. Herein, we demonstrate highly reliable NDR photodetectors by constructing a MoS₂/p-Si heterostructure. Owing to the formation of a MoS₂ layer with uniform thickness by the plasma-enhanced sulfurization process, a 100% yield with high uniformity (peak-to-valley ratio = 1.195 ± 0.065) was achieved for 120 devices. Furthermore, the proposed NDR photodetectors exhibit unprecedented high cycle-to-cycle endurance, which maintains their NDR characteristics through 100 000 consecutive sweeps without operational failure. This work paves the way for the development of a reliable NDR device and reports unprecedented results of high uniformity, reproducibility, and robustness for practical applications.

Microwave-assisted functionalization of zinc oxide nanoflowers (ZnO NFs) with palladium nanoparticles (Pd NPs) is demonstrated to realize high-performance chemiresistive-type hydrogen (H₂) gas sensors operating at room temperature (RT). The developed gas sensors exhibit a high response of up to 70% at 50 ppm and a theoretical detection limit of 10 ppb. The formation of ZnO NFs with an enhanced specific surface area and their functionalization with Pd NPs are investigated through various characterizations. Furthermore, the optimization of microwave absorption upon the structural incorporations between nanostructures (NF–NPs) is investigated for solution-based functionalization at low temperatures (below 120 °C) for short process times (within 1 min), compared to the conventional thermal annealing at 250 °C for 1 h. Highly sensitive and selective ZnO-based gas sensors enabling the detection of H₂ gas molecules at 300 ppb concentration at RT exhibit a short response/recovery time of below 3 min and a good selectivity toward different gases including nitric oxide, carbon monoxide, and oxygen. The successful functionalization of nanostructured metal oxide semiconductors (MOSs) with metal NPs via effective and practical microwave absorption enhances the potential on highly sensitive and selective chemiresistive-type MOS-based gas sensors operating at RT without additional heaters or photogenerators.

Cu₁₂Sb₄S₁₃ has aroused great interest because of its earth-abundant constituents and intrinsic low thermal conductivity. However, the applications of Cu₁₂Sb₄S₁₃ are hindered by its poor thermoelectric performance. Herein, it is shown that Gd substitution not only causes a significant increase in both electrical conductivity σ and thermopower S but also leads to dramatic drop in lattice thermal conductivity κ_L. Consequently, large ZT reaches 0.94 at 749 K for Cu_11.7Gd_0.3Sb₄S₁₃, which is ∼41% higher than the ZT value of undoped sample. Rietveld refinements of XRD results show that accompanying inhibition of impurity phase Cu₃SbS₄, the number of Cu vacancies increases substantially with substituted content x (x ≤ 0.3), which leads to reduced κ_L owing to intensive phonon scattering by the point defects and increased σ arising from the charged defects (V_Cu^’). Crucially, synchrotron radiation photoelectron spectroscopy reveals substantial increment of electronic density of states at Fermi level upon Gd substitution, which is proven, by our first-principle calculations, to originate from contribution of Gd 4f orbit, resulting in enhancement of S. Our study provides us with a new path to enhance thermoelectric performance of Cu₁₂Sb₄S₁₃.

An extremely high quantity of small pieces of synthetic polymers, namely, microplastics, has been recently identified in some of the most intact natural environments, e.g., on top of the Alps and Antarctic ice. This is a “scary wake-up call”, considering the potential risks of microplastics for humans and marine systems. Sunlight-driven photocatalysis is the most energy-efficient currently known strategy for plastic degradation; however, attaining efficient photocatalyst–plastic interaction and thus an effective charge transfer in the micro/nanoscale is very difficult; that adds up to the common challenges of heterogeneous photocatalysis including low solubility, precipitation, and aggregation of the photocatalysts. Here, an active photocatalytic degradation procedure based on intelligent visible-light-driven microrobots with the capability of capturing and degrading microplastics “on-the-fly” in a complex multichannel maze is introduced. The robots with hybrid powers carry built-in photocatalytic (BiVO₄) and magnetic (Fe₃O₄) materials allowing a self-propelled motion under sunlight with the possibility of precise actuation under a magnetic field inside the macrochannels. The photocatalytic robots are able to efficiently degrade different synthetic microplastics, particularly polylactic acid, polycaprolactone, thanks to the generated local self-stirring effect in the nanoscale and enhanced interaction with microplastics without using any exterior mechanical stirrers, typically used in conventional systems. Overall, this proof-of-concept study using microrobots with hybrid wireless powers has shown for the first time the possibility of efficient degradation of ultrasmall plastic particles in confined complex spaces, which can impact research on microplastic treatments, with the final goal of diminishing microplastics as an emergent threat for humans and marine ecosystems.

Porous hollow microsphere (PHM) materials represent ideal building blocks for realizing diverse functional applications such as catalysis, energy storage, drug delivery, and chemical sensing. This has stimulated intense efforts to construct metal oxide PHMs for achieving highly sensitive and low-power-consumption semiconductor gas sensors. Conventional methods for constructing PHMs rely on delicate reprogramming of templates and may suffer from the structural collapse issue during the removal of templates. Here, we propose a template-free method for the construction of tin oxide (SnO₂) PHMs via the competition between the solvent evaporation rate and the phase separation dynamics of colloidal SnO₂ quantum wires. The SnO₂ PHMs (typically 3 ± 0.5 μm diameter and approximately 200 nm shell thickness) exhibit desirable structural stability with desirable processing compatibility with various substrates. This enables the realization of NO₂ gas sensors having a superior response and recovery process at room temperature. The superior NO₂-sensing characteristic is attributed to the effective gas adsorption competition on solid surfaces benefiting from efficient diffusion channels, enhancing the interaction of metal oxide solids with gas molecules in terms of the receptor function, transducer function, and utility factor. In addition, the one-step deposition of SnO₂ PHMs directly onto device substrates simplifies the fabrication conditions for semiconductor gas sensors. The desirable structural stability of PHMs combined with the functional diversity of metal oxides may open new opportunities for the design of functional materials and devices.

Transition metal chalcogenides (TMCs) have gained worldwide interest owing to their outstanding renewable energy conversion capability. However, the poor mechanical flexibility of most existing TMCs limits their practical commercial applications. Herein, triggered by the recent and imperative synthesis of highly ductile α-Ag₂S, an effective approach based on evolutionary algorithm and ab initio total-energy calculations for determining stable, ductile phases of bulk and two-dimensional Ag _x Se_1–x and Ag _x Te_1–x compounds was implemented. The calculations correctly reproduced the global minimum bulk stoichiometric P2₁2₁2₁-Ag₈Se₄ and P2₁/c-Ag₈Te₄ structures. Recently reported metastable AgTe₃ was also revealed but it lacks dynamical stability. Further single-layered screening unveiled two new monolayer P4/nmm-Ag₄Se₂ and C2–Ag₈Te₄ phases. Orthorhombic Ag₈Se₄ crystalline has a narrow, direct band gap of 0.26 eV that increases to 2.68 eV when transforms to tetragonal Ag₄Se₂ monolayer. Interestingly, metallic P2₁/c-Ag₈Te₄ changes to semiconductor when thinned down to monolayer, exhibiting a band gap of 1.60 eV. Present findings confirm their strong stability from mechanical and thermodynamic aspects, with reasonable Vickers hardness, bone-like Young’s modulus (E) and high machinability observed in bulk phases. Detailed analysis of the dielectric functions ε(ω), absorption coefficient α(ω), power conversion efficiency (PCE) and refractive index n(ω) of monolayers are reported for the first time. Fine theoretical PCE (SLME method ∼11–28%), relatively high n(0) (1.59–1.93), and sizable α(ω) (10⁴–10⁵ cm^–1) that spans the infrared to visible regions indicate their prospects in optoelectronics and photoluminescence applications. Effective strategies to improve the temperature dependent power factor (PF) and figure of merit (ZT) are illustrated, including optimizing the carrier concentration. With decreasing thickness, ZT of p-doped Ag–Se was found to rise from approximately 0.15–0.90 at 300 K, leading to a record high theoretical conversion efficiency of ∼12.0%. The results presented foreshadow their potential application in a hybrid device that combines the photovoltaic and thermoelectric technologies.

The Faraday effect is a magneto-optical (MO) phenomenon that causes the plane of linearly polarized light to rotate when passing through a medium subjected to a parallel magnetic field. Informed by the established quantum mechanical model developed by Buckingham and Stephens, we sought to identify molecules that would exhibit large MO responses. Magnetic circular dichroism studies of ferrocenium in the 1970s revealed its potential as an MO material; however, it has not been evaluated in the context of Faraday rotation and thin-film optical applications. Herein, we report near-infrared (NIR) Faraday rotation in thin films of decamethylferrocenium/poly(methyl methacrylate) composites with maximum Verdet constants of −3.45 × 10⁴ deg T^–1 m^–1 at 810 nm (absorbance = 0.09) and −1.44 × 10⁴ deg T^–1 m^–1 at 870 nm (absorbance = 0.01). These polymer–metallocene thin films deliver larger Verdet constants than commercially used NIR inorganic Faraday rotators and are facile and inexpensive to produce. The temperature dependence and distinct lineshape of the MO responses observed in decamethylferrocenium radical cations, decamethylmanganocene, and chromocene are in accordance with the quantum mechanical model. The observation of a strong C-term Faraday rotation in solid-state organometallic materials provides the groundwork for the development of high-performance metallocene-based Faraday rotators.