A Semi-Interpenetrating Network Sorbent of Superior Efficiency for Atmospheric Water Harvesting and Solar-Regenerated Release

Water is readily available nearly anywhere as vapor. Thus, atmospheric water harvesting (AWH) technologies are seen as a promising solution to support sustainable water production. This work reports a novel semi-interpenetrating network, which integrates poly(pyrrole) doped with a hygroscopic salt and 2D graphene-based nanosheets optimally assembled within an alginate matrix, capable of harvesting water from the atmosphere with a record intake of up to 7.15 gw/gs. Owing to the incorporated graphene nanosheets, natural sunlight was solely used to enable desorption, achieving an increase of the temperature of the developed network of up to 71 °C within 20 min, resulting in a water yield of 3.36 L/kgS in each cycle with quality well within the World Health Organization standard ranges. Notably, after 30 cycles of sorption and desorption, the composite hydrogel displayed unchanged water uptake and stability. This study demonstrates that atmospheric water vapor as a complementary source of water can be harvested sustainably and effectively at a minimal cost and without external energy input.


S1.1 Morphology (SEM and EDS)
The morphology of the composites was analyzed using SEM images before and after the addition of PPyCl to the alginate matrix.The SEM imaging of GO (Figure S3 (a)) exhibits crushed sheets and a lamellar surface.The existence of CaCl 2 and LiCl in the composite was demonstrated by energy dispersive X-Ray spectroscopy (EDS) and X-Ray diffraction (XRD).
Elements such as carbon (C), oxygen (O), chloride (Cl), nitrogen (N), and calcium (Ca) can be seen in Figure S3 (b)owing to the existence of PPyCl, GO, CaCl 2 , and LiCl in BAGY.
Figure S3 (a) SEM images of GO and (b) EDS spectra and atomic analysis of BAGY.

S1.2 Surface area analysis and porosity characteristics
The textural properties of PPyCl, BAG, and BAGY, including pore size, surface area, and pore volume, were measured using a Micromeritics 3Flex analyzer.PPyCl has a low BET surface area of 3.7 m 2 /g, as shown in Table S1, however, BAGY revealed a type II isotherm and exhibited larger surface area (37.7 m 2 /g).The specific surface area of BAG was 12.2 m 2 /g, which is a larger value than pure crosslinked binary alginate (~4 m 2 /g), which can be due to the fact that the porosity of gel was further increased by the addition of GO, while BAGY, which combines PPyCl with alginate and GO, had a higher surface area than BAG The latter is beneficial as typically, the greater the specific surface area, the higher the adsorption capacity. 1 However, the pore size and volume are also important factors in enhancing the adsorption performance. 2The textural characteristics of the composite sorbents are summarized in Table S1.Table S1 The textural parameters of PPyCl and composites obtained by BET analysis.

S1.3 Structural analysis (XRD)
Figure S5 (a) displays the XRD patterns for GO, CaCl 2 , and LiCl.It was possible to see the typical GO peak at 11.6°, which corresponds to the (001) crystal plane. 3,4The interlayer spacing of GO was found to be 0.76 nm by using the Bragg's equation, which is greater than that of pure graphite (0.34 nm).The effective functionalization and resulting introduction of oxygen functional groups on the graphene sheets during the oxidation process has resulted in the rise in interlayer space. 5,6cording to the XRD patterns shown in Figure S4, SA and PPyCl are amorphous polymers, which is consistent with previous studies, 7,8 yet, the PPyCl pattern exhibits a wide peak between 25 and 35°, which is attributed to an interplanar d-spacing (3.45 Å) and the π-π interaction of the polypyrrole chain. 9No new distinctive diffraction peaks were seen in the XRD pattern of the surface of the BAGY beads Figure S5

S1.4 Chemical interactions (FTIR)
Using Fourier transform infrared spectroscopy (FTIR) in the wavenumber range of 4000-400 cm -1 , the physicochemical features of PPyCl, salts, alginate, GO, and the resulting composites were examined.PPyCl exhibited three main characteristic bands (Figure S6).The C=C and C-C in-plane bending vibrations of pyrrole rings are witnessed near 1451 and 1533 cm -1 . 10The distinctive band at 780 cm -1 demonstrated the PPy ring's C-H deformation vibration. 10The broad band at 900 cm -1 reveals the C-N stretching vibration. 11Additionally, the C=N stretching and =C-H in-plane vibrations have bands of 1160 cm -1 and 1300 cm -1 , respectively. 11,12Also, the band around 1039 cm -1 is ascribed to the in-plane deformation of N-H bond. 12The bands at the expanded region between 3680-2800 cm -1 and at 1640 cm -1 correlate with the vibration of OH stretching due to the remaining H 2 O in the sample, which could be attributed to intra and intermolecular hydrogen-bond interactions of aliphatic and phenolic hydroxyl groups. 10om the GO spectra, it is clear that GO is functionalized by a variety of oxygen-enriched groups, including carboxyl, hydroxyl, carbonyl, and epoxy groups. 13The water molecules that are adsorbed on the surface of GO may be the cause of the wide band across the 3686 to 3000 cm -1 range. 14Characteristic O-C=O groups are found to have distinctive bands at 2083 cm -1 , 15 while bands at 1720, 1617, 1238, and (1052 and 964) cm -1 are linked to stretching vibrations of C=O in carbonyl groups such as esters, ketones, and carboxylic acids on the sheet's edges and defects, 1,[15][16][17][18] Unoxidized aromatic C=C stretching vibrations in the sp2 carbon skeletal network, 16,17 C-O epoxide stretching, 15 and alcoholic C-O stretching vibrations, 15 respectively.
The spectra of sodium alginate (SA) exhibit a broad band at 3276 cm -1 , which is due to O-H stretching vibrations in hydroxyl, carboxylic, phenolic, and chemisorbed water. 7,13,16,17ditionally, distinctive bands for the -CH symmetric stretching vibrations of the aliphatic -CH 2 and -CH 3 groups are seen around 2902 cm -1 , 7,16-22 1610 cm -1 for the asymmetric stretching vibrations of -COOH, 7,17,19,20,23 -C-C/C=C, 21 and bending vibration of O-H, 14,24 at 1537 cm -1 for tensile vibration of isolated C=C bond 1 , at 1415 cm -1 for the symmetric -COO stretching vibration, 16,17,[19][20][21]23 at 1390 cm -1 for -CH 2 (bending), 7 at 1373 -1294 cm -1 for C-C bending vibrations, 25 at 1114 cm -1 for vibration peak of -C-OH, 22 at 1081-1024 cm -1 for C-O-C/ C-O (stretching) vibrations 7,14,20,24,26 with contributions from C-C-H and C-O-H, 18,19,25 at 944 cm - 1 for the functional groups of guluronic acid, 27 at 808 cm -1 or linkage of mannuronic and guluronic units, 25 at 773 cm -1 for the functional groups of mannuronic acid, 27 and at 626 cm -1 for aromatic rings. 20The physicochemical interactions between the alginate, GO, and PPyCl were further examined on the basis of the FTIR results.From FTIR spectra, a strong affinity for water was revealed for BAGY as per the broad hydroxyl band from the polymer backbone between 3250 and 3500 cm -1 and that at 1610 cm -1 related to the hydroxyl group of structural water (Figure S6 (b)).28 The intensities of these bands for the BAGY samples were significantly higher compared to SA and PPyCl, confirming the higher water sorption capability.20 The band corresponding to -OH groups in the crosslinked alginate-based composites shifted to a higher wavenumber as a result of the interactions between the alginate chains forming hydrogen bonds, The formation of these ionic and hydrogen bonds is anticipated to enhance the mechanical properties. Ater gelation, compared to pure SA, several alginate characteristic bands widened, and their relative intensities altered, demonstrating the presence of potent ionic interactions between the Ca 2+ or Li + ions and the alginate chains.In general, the substitution of Li + and Ca 2+ for sodium ions in the alginate structure should not dramatically alter the spectrum of sodium alginate because no new chemical bonds are being introduced into the system.
However, the position of carboxylic anion -related bands might reveal the ion exchange process.The attraction between the employed cations and the carboxylic anion varies because the Na + , Li + , and Ca 2+ have distinct electronegativities. 20 It was possible to see a shifted band with enhanced intensity at 1610 and 1415 cm -1 that corresponds to the stretching vibrations of the COO -groups, symmetrically and asymmetrically.These alterations might be attributed to the production of the carboxylate group during the cross-linking with Ca 2+ and Li + , demonstrating a robust crosslinking and interaction between alginate chains and salt cations. 14 addition to the alginate peaks, a new weak band at 590 cm -1 also emerged.This band is ascribed to the nonreacted chloride ions that persisted in the system even after the products had been washed in ethanol.These residual salts also have an impact on the intensify of the peak at 1610 cm -1 . 20The interaction between the components involved during synthesis may be seen in the intensification and modest repositioning of bands below 1500 cm -1 , which may be due to the bands of the alginate backbone structure overlapping with the polypyrrole bands.showing a peak at 200.9 eV, corresponding to Cl -(-NH + -), Cl -(H 3 O + ) and covalent chlorine species (-Cl) 30 .The PPyCl produced may then be hypothesized to be oxidized and the Cl to be bonded to the PPy chain into a doped-state retained within the PPyCl-alginate composite. 30reover, the peaks at 347.4 and 350.9 eV in Figure S8

S1.6 Mechanical and rheological properties
Viscoelasticity is an essential feature of hydrogels and is often tested using an oscillation mode rheometer.The linear viscoelastic zone must first be identified by amplitude scanning since the characteristic constants of the hydrogel can only be acquired in this region during rheological investigation.Because polymeric hydrogels are viscoelastic materials, the addition of an additive might change their mechanical characteristics. 30,32The storage modulus (G′) and loss modulus (G′′) of the gel network, respectively, show how much energy is held therein and process is finished at around 190 °C.The graph shows that PPyCl loses considerable weight (9-10 wt.%), which confirms its high hydrophilicity responsible for moisture absorption from the air.Previous research has indicated that PPyCl absorbs around 10 wt.% of water from air. 33ditionally, the TGA graph in Figure S10 (a) illustrates that the weight loss of sodium alginate (SA) reaches 18% in the temperature range of 50 °C to 250 °C.This weight loss is mainly due to the dehydration of the material and the volatilization of other volatile substances.Only a major considerable pyrolysis stage was found to happen at 250-300 °C, which is caused by the degradation of the main molecular chain of alginate.
The structure of alginate-based polymeric composites contains double bonds, which makes them more vulnerable to high temperatures. 20The thermal behavior of BAG and BAGY shows a two-step process (Figure S10  Drying the BAGY samples up to 120 °C did not damage the polymer structure as confirmed by TGA analysis.These samples can be dehydrated up to 120-130 ℃ in a short heating time, but when the desorption time is prolonged, they can be completely dehydrated at 60-80 ℃.A minor weight loss of 1-3% can be observed due to extra dehydration under the testing conditions, which may be extended to 180-190 °C because of the presence of residual salt hydrates within the polymeric matrix.The second stage of weight loss, 10-15% between 190°C to 230°C, is due to the disintegration of glycosidic bonds, the decomposition of alginate, and the depolymerization resulting in the breaking of C-O and C-C bonds. 25,26At temperatures up to 400°C, pyrolysis of oxygen-containing groups in both GO and alginate occurs, 34 mostly the carboxylic groups from the carbon skeleton, occurs, which leads to the release of CO 2 , H 2 O, and other small molecules and contributes to mass loss. 13gure S10 (a) TGA profiles of PPyCl, SA, salts, and the developed composites, and (b) residual weight of composites at the terminal temperature of the TGA analysis.

S1.8 DSC analysis
The DSC heating and cooling curves of all samples reveal the occurrence of a peak for melting that is endothermic and a peak for solidification that is exothermic (Figure S11).
BAGY has melting and solidification temperatures higher than 480 °C.Additionally, for alginate-based samples, endothermic bands between 200°C and 250°C and at 450°C are linked to the degradation temperature of the alginate and GO backbone, 16 This confirms the results from TGA that all samples have high stability below 200°C and that PPyCl plays a role in enhancing the thermal stability. 25e DSC heating curves show irreversible peaks, which vanish in the cooling curves, indicating that they are likely caused by moisture desorption and irreversible degradation.As opposed to that, the reversible peaks correspond to phase transition states or phase changes.
So, DSC analysis can be used to qualitatively evaluate the evaporation enthalpy for all samples and to demonstrate how temperature affects the adsorbed water vapor.As seen in Figure S11, the vaporization enthalpy of PPyCl is 3489 J/g at ~126 °C, and that of BAGY is 3945 J/g at ~88 °C. 10 Figure S11 DSC heating and cooling curves of (a) PPyCl and (b) BAGY.

S1.9 Raman spectroscopy
According to Figure S12, the disorder-induced D band at 1330 cm -1 and G band at 1602 cm -1 can be observed.The presence of the D band is caused by the disorder of the sp2 carbon network, while the presence of the G band is related to the graphitic hexagon-pinch mode, which confirms the presence of GO in the sample. 14The Raman spectrum of polypyrrole is affected by the excitation wavelength due to the resonance or near-resonance conditions that come from the localized structures formed within the polymer.These effects, which may be linked to the increasing double-bond character of the Cα-α, and Cβ-β bonds, and the decreasing electron density along Cα-β, can be seen in the shifts and the relative intensities of the absorption bands and their positions.Figure 2 (a) displays the Raman spectrum of polypyrrole.
The peaks at 1576, 1471, 1314, 1063, and 980 cm -1 confirm the presence of polypyrrole, with the peaks representing C=C, C-C, C-N, C-H, and the aromatic ring, respectively.This indicates the composition of the polypyrrole, and verifies the synthesized material. 35Additionally, the peaks at 980 and 1063 cm -1 with the quinonoid polaronic structure indicate the presence of the doped PPy structure. 36e BAG sample showed peaks with a shift in the D band to 1335 cm -1 and G band to 1605 cm -1 after collecting water from the air, further confirming the successful addition of GO into the alginate matrix (Figure S12).The intensity ratio of BAG (ID/IG = 1.08) is almost the same as that of GO (ID/IG = 1.02), indicating that the number of defects and oxygen functionalities in GO stayed unchanged. 14This can be explained by the fact that incorporating GO into the alginate matrix did not cause any noticeable destruction to the sp2 carbon network of GO. [37][38][39] The Raman spectrum of the BAGY (Figure 2

S1.11 UV-VIS-NIR spectroscopy
The efficiency of solar-driven water desorption using a composite material is related to its ability to absorb light and convert it into heat. 20The composite developed herein contained GO as one of its constituents to enhance this action.When light is absorbed by the composite, electrons are excited to a higher energy state, and when they return to the ground state, nonradiative transitions occur, which produce heat.Research has shown that the near-infrared (NIR) absorbance spectrum of water has strong absorption intensities between 1400 nm and 2500 nm. 29The narrow absorption wavelength of water makes it challenging to achieve high efficiency in solar-driven water desorption.To improve efficiency, the water sorbent should have increased absorption in the NIR region below 1400 nm, which can compensate for the limited absorption range of water, which corresponds to the broad range of the standard solar spectrum.The ultraviolet-visible-near-infrared (UV-vis-NIR) absorption spectra of the samples were collected over the full spectrum range of 200-1400 nm, which is crucial for effective light harvesting of solar radiation.
Polypyrrole (PPy) is a low-cost, easily synthesized, and biocompatible black polymer that has been widely used in solar evaporation due to its excellent light absorption properties. 10Graphene oxide (GO) is also incorporated as a photothermal material in the composite due to its strong absorption in the visible light range, which dominates sunlight.The black color of GO also enhances the photo-absorption of the composite samples.The spectral properties of the composites containing PPyCl and GO (5 wt%) and those without them were measured over a wavelength range from 200 to 1400 nm.The results show that the light absorption of BA (alginate without GO) was 54%.However, the PPyCl and PPyCl/alginate (BAY) samples absorbed ~98% and 94% of light respectively, with very little transmittance and reflectance (less than 0.1% and 5%, respectively), as shown in Figure S14.When GO was incorporated S1.12 Moisture capture optimization A screening strategy was followed to optimize the water uptake of the developed composite.Sodium alginate concentrations were varied across different internal (M/G) ratios, assessing their impact on moisture capture (Figure S15).All details for sample compositions are presented in Table S2.For all M/G ratios and SA concentrations, this optimization procedure identified optimal alginate concentrations for each M/G ratio, notably 1.23 wt.% for an M/G ratio of 1:2, demonstrating the highest water uptake.Additionally, we investigated the role of salt solution saturation in the crosslinking process, finding that higher salt concentrations in the gelation solutions enhanced water sorption by retaining more residual salt within the beads (Figure S16).We also examined the effects of varying polypyrrole chloride (PPyCl) to sodium alginate (SA) ratios on water sorption, as shown in Figure S17.This allowed us to pinpoint the sample configurations with the best performance under varying RH conditions.

S1.13 Sorption mechanism and isotherm modelling
To fit the experimental results of moisture sorption on BAGY, four adsorption isotherm models were used: Langmuir (Figure S19 S3.The Langmuir model was found to be inadequate for describing the isotherm of BAGY, while the Freundlich model, which considers adsorption on uneven and diverse surface sites, provided a moderate match.Based on the high Adj.R 2 correlation coefficient values, it was determined that the FHH and GAB isotherms were the most suitable for fitting the experimental data of BAGY.The FHH model is commonly used to describe the sorption of water vapor on clay particles, and it was found that the water vapor sorption pattern for the BAGY is similar to that for clays. 40The FHH model assumes that when the relative humidity is high, capillary condensation and the presence of multiple layers within the material cause water to fill the internal structure through hydrogen bonding and Van der Waals interactions. 41,42The FHH model posits that a gradient of sorption potential exists and is determined by the distance between the surface of the sorbent and the sorbate layer. 43The BAGY's experimental data being consistent with the FHH model, indicates the presence of capillary condensation and enhanced interactions between water molecules and sorption sites at high relative humidities.The model was also used to calculate the single-layer adsorption capacity (q m ), and it was found that these values were higher at lower temperatures and decreased as temperature increased, supporting that water uptake is greater at lower temperatures.
Additionally, the experimental data was found to have a strong correlation with the GAB model.The GAB model can be used to calculate the amount of coverage of the sorbate molecules, known as bounded water, by determining the monolayer adsorption capacity (q m ).
It was observed that at lower temperatures, q m had a higher value, which decreased as the temperature increased.Additionally, the values of the parameter c G , which indicates the presence of linkage between the sorbate and adsorbent, decreased with increasing temperature.

S1.14 Estimation of isosteric heat of sorption
The isochoric heat of sorption (ΔH s ) was determined using the Clausius-Clapeyron equation (Equation S1): 44 (S1) The Clausius-Clapeyron equation relates the change in heat of adsorption (ΔH s ) to the change in pressure (p) and temperature (T).In this equation, R and T represent the ideal gas constant and temperature, respectively, and C is an integrating constant.To calculate ΔH s , the sorption isotherms were converted into isosteres by plotting them as ln(p) versus 1/T (Figure S20) for different water vapor uptakes.The slope (-ΔH s /R) was then used to determine the ΔH s .
Figure 2 (e) shows the graph of ΔH s at various equilibrium water uptakes, and Table S4 lists the values of ΔHs as well as the corresponding correlation coefficients.The ΔH s values were found to be much higher at lower sorption capacities because, at lower relative humidity levels, water molecules were strongly bound to the matrix.However, at higher water uptakes and RH levels, most of the sorbed water was present as weakly bonded liquified water, resulting in relatively low ΔH s values.As the humidity levels increased, clusters of water molecules grew and began to penetrate deeper into the inner structure of the sorbent and fill the pores.This is supported by the fact that the ΔHs values of BAGY were found to be in the range of 65-44 kJ/mol, with values of < 50 kJ/mol for coverage higher than 1 g/g, revealing physical interactions (Table S4 and Figure 2 (e)).
Additionally, the desorption enthalpy was determined by conducting sorption tests using a DSC instrument in combination with a modular humidity generator under a nitrogen purging environment.One of the main assumptions was that the kinetics are same during TGA and DSC experiments.This method allowed for the determination of the enthalpy of desorption of water vapor for BAGY at different relative humidity levels (10-90% RH).The DSC tests were performed with two temperature ramps to remove the heat history of the material.Firstly, samples were heated to 150 °C and 0% RH at a rate of 1 °C/min, then cooled down to 23 °C with a cooling rate of 10 °C/min.At the end of the first ramp, the sample is considered to be in a dry state with no leftover water present.The enthalpy of sorption was calculated by applying the following equation: 45 (Equation S2) During these experiments, the thermal energy (Q HFS ) measured by the heat flux sensor is related to the amount of vapor sorbed by the sample (m s ).This amount is determined by comparing simultaneous TGA results with the water uptakes obtained from the gravimetric analysis done using the Q5000SA sorption instrument.The data for the enthalpies of sorption and release for BAGY are shown in Table S5.

S1.15 Energy transfer/balance during water capturing
The process of converting vapor into liquid is exothermic, while the polymer dissolution of endothermic.Due to the high molecular weight, the interaction between polymer chains is strong, and water molecules needs to insert into the spaces between the polymer chains, which requires energy.The balance between these two processes, along with any uncontrolled heat loss to the surroundings, determines the overall temperature change of the sample.The temperature change during moisture sorption is used to confirm this claim.At the beginning of the sorption test, an increase in the temperature of sample has been recorded from 24 to 27 °C as a result of the initiation of the endothermic water sorption (Figure S21).While no temperature change could be observed after some time, suggesting that the overall BAGY's heating or cooling is negligible due to the dynamic equilibrium of thermal energy release and dissipation to surroundings.Dissolution appears not to have occurred, as evidenced by the unchanging weight of the BAGY sample even after several sorption/desorption cycles and the absence of any associated bands in DSC curves, suggesting that the generated energy from sorption was not sufficient to activate the dissolution of the polymer.This might be owing to BAGY's strong tendency for water capture and a lack of heat to stimulate polymer disintegration, thus promoting the composite's stability.
Figure S21 The temperature profile of BAGY during the water capturing process.

S1.16 Energy balance in the beads during desorption under sun radiation
The analysis of heat released from the sorbent when it is exposed to an open environment is presented in Equation S3.The total energy received from the sun equals the energy exchanged through radiation with the environment, energy transferred into the system by convection, heat used for evaporation, and finally, heat conducted (Q cond ) to the lower layers.The total energy that leaves the system can be separated into three parts: reflection loss (3%), heat loss through convection (17.1%), and heat loss through radiation (21.8%).The remaining energy, which is 58.1%, is used for water evaporation and heat conduction.
However, when taking into account the insulation of the bottom face of the box and the energy balance boundaries around the material, heat conduction is not considered a loss from the system.Despite this, the low thermal conductivity causes a high thermal gradient on the surface.This leads to an increased evaporation rate on the surface, resulting in an increase in mass transfer from the core to the surface by diffusion.

S1.17 Sorption kinetics
The system's ability to extract more water from the external environment within a given time due to faster kinetics, which allows for more cycles of moisture capturing to occur in a shorter period of time, was also evaluated.The experiment was conducted by exposing the material to N 2 gas and atmospheric air with varying RH levels (10%, 40%, and 70%) at a temperature of 23 °C in a testing chamber after it had been fully dried.The material was regenerated at temperatures of 60, 70, and 80 °C to study its regeneration behavior over time.
The results showed that the material's rate of water uptake was the highest at the onset of the experiment, and then gradually decreased as the sorption process continued (Figure 2 (f) and Figure S22 (a)).
In order to better understand the kinetics of water capture by BAGY, two kinetic models were used, the pseudo-first-order and pseudo-second-order models.The parameters for these models are shown in Table S6 and the results of the experimental dataset fitting are shown in Figure S22 (b).Both models have correlation coefficients greater than 0.9, indicating that they are able to effectively depict the sorption process at different RH levels.Specifically, the pseudo-first-order model showed a correlation coefficient of 0.99 at 40 and 70 RH %, making it an effective model for understanding absorption at these levels.The pseudo-second-order model also had a high correlation coefficient of 0.99 and predicted equilibrium water uptake that was close to the experimental value.This suggests that the pseudo-second-order model accurately captures the behavior of BAGY and that BAGY sorbs water through both physical and chemical sorption.

S1.18 Optimization of bed configuration and cycle time
To better understand and design a device for real-world moisture capture application, experiments were conducted to determine the time it takes for BAGY to generate water spills around the sorbent's bead.Two plates of material were used, one with a single layer of BAGY beads and the other with multiple layers.These plates were placed in different RH conditions and were observed for water spill formation to occur.The time of water spill formation and the samples' weight were recorded (Figure S23).At 20% RH, no water spill was observed.The area of each circle in Figure S23 represents the amount of water uptake in g/g of material when water leakage starts.The results show that the single layer structure can collect more vapor, and water spill formation occurs much faster.This can be attributed to the fact that in multiple layers, the bottom layers are not directly exposed to air and the water sorbed by the upper layer passes in the lower layers through the beads via diffusion, thus the latter cannot contribute directly in AWH.These experiments suggest that BAGY is better used in a single layer configuration.Additionally, cycles can be designed with short humidification times (75, 69, 50, 37 and 20 min for 40%, 50%, 60%, 70% and 80%, respectively) followed by desorption, if water spills are needed to be avoided in real system design to reduce the possibility of subsequent deliquescence.Another approach is to use a porous matrix or conventional desiccant to support the developed composite, and any possible spilled water can be sustained in the sorbent.

Figure
Figure S1 BAGY beads (a) before drying displaying their uniformity as-synthesized and (b)

Figure
Figure S2 Water sorption test set up (humidity box)
(b), proving the presence of wellcrosslinked amorphous alginate and that there are no salt hydrates on the external surface of the beads.However, the XRD pattern of finely ground BAGY (Figure S5 (b)) show characteristic peaks of the salts, which are attributed to residual salt particles distributed in the internal structure after washing, as well as GO.The CaCl 2 and LiCl peaks seen in BAGY demonstrate the effective replacement of Na ions in the cavities of alginate by Ca and Li ions.

FigureS1. 5
Figure S6 (a) FTIR spectra of PPyCl, SA, GO, LiCl, and CaCl 2 .(b) Comparison of FTIR (c) were attributed to Ca 2p3/2 and Ca2p1/2, respectively, showing that the calcium atom was bivalent.The findings supported the existence of alginate, GO, salts, polypyrrole, carboxyl, epoxy, Cl, pyrrole N, and Ca components in the composite beads.

Figure
Figure S7 XPS wide spectra of PPyCl, BAG, and BAGY.
Figure S10 (a) shows the TGA profiles of PPyCl, SA, CaCl 2 , and LiCl, and how salts (a)).The first stage is the evaporation of water on the surface and trapped inside the inner structure, which may be up to 120-130 °C.Compared to a BAG sample, the TGA profile of BAGY showed a slight increase in the residual weight after the test, indicating that the thermal stability of the BAGY sample has improved after including PPyCl in the network (Figure S10 (b)).
(a)) also shows characteristic vibrational peaks of PPyCl.However, it is clear that the spectra of the PPyCl and BAGY samples areS1.10Light/heating absorption kineticsA simulated sunlight source was utilized to assess the samples' ability to convert light to heat since solar radiation provides the thermal energy needed for the desorption process.The surface temperature of BAG, BAY, BAGY, and PPyCl increased by about 30 to 40 °C over the first 10 min, but only by about 9 °C for BA (FigureS12).The temperatures then reached a plateau at 60 °C for BAG, 62 °C for BAY, 58 °C for PPyCl, and 71 °C for BAGY, indicating that the lost energy from surface was in equilibrium with the absorbed solar energy.But after 120 min, the temperature of the BA sample gradually rose to 50 °C and stayed there while being exposed to the same amount of light.The homogenous temperature distribution on the surface of the beads shows that the distribution of PPyCl and GO in the samples is uniform, as confirmed by the IR image in the inset of FigureS13.

Figure
Figure S13 Light and heat conversion kinetics under 1 sun irradiation.

Figure
Figure S15 (a) Dependence of water uptake on SA concentration with M/G ratio of 0.5, (b)

Figure S16
Figure S16 The impact of saturation percentage of gelation salt solutions on BAGS water

Figure
Figure S20 Plots of the ln (p) versus 1/T at various water uptakes.

Figure
Figure S22 (a) Water uptake/release kinetics measurements for BAGY from atmospheric air at

Figure
Figure S23 Water spill formation time (y-axis) at different relative humidities and water uptake

FigureFigure
Figure S24 Temperature profile of ambient air, cover, sample, and ambient RH in (a) indoor 11,22

Table S2
Amount and compositions of samples with different SA concentrations and M/G ratios.

Table S3
Different isotherm model parameters for the water absorption on BAGY.

20 ( ) sun α sun = α low temp σ (T 4 surface -T 4 ∞ ) + h (T surface -T ∞ ) + ṁ h evap + Q cond
T surface , T ∞ , h, ṁ and h evap are absorptivity for solar irradiance, absorptivity of radiation at low-temperature, Stefan-Boltzmann constant, the surface temperature, the temperature of surrounding, the coefficient of convective heat transfer, the mass flux of evaporation, and the enthalpy of vaporization, respectively.The α sun and α low temp for black material can be considered equal 97%.T surface and T ∞ are almost 69 ℃ and 23 ℃, (Equation S3)   where α sun , α low temp , σ,