Antimony Oxide Research Articles

Thermochromic Ni(II) Organometallics With High Optical Transparency and Low Phase-Transition Temperature for Energy-Saving Smart Windows.

Thermochromic smart windows with rational modulation in indoor temperature and brightness draw considerable interest in reducing building energy consumption, which remains a huge challenge to meet the comfortable responsive temperature and the wide transmittance modulation range from visible to near-infrared (NIR) light for their practical application. Herein, a novel thermochromic Ni(II) organometallic of [(C2 H5 )2 NH2 ]2 NiCl4 for smart windows is rationally designed and synthesized via an inexpensive mechanochemistry method, which processes a low phase-transition temperature of 46.3 °C for the reversible color evolution from transparent to blue with a tunable visible transmittance from 90.5% to 72.1%. Furthermore, cesium tungsten bronze (CWO) and antimony tin oxide (ATO) with excellent NIR absorption in 750-1500 and 1500-2600nm are introduced in the [(C2 H5 )2 NH2 ]2 NiCl4 -based smart windows, realizing a broadband sunlight modulation of a 27% visible light modulation and more than 90% of NIR shielding ability. Impressively, these smart windows demonstrate stable and reversible thermochromic cycles at room temperature. Compared with the conventional windows in the field tests, these smart windows can significantly reduce the indoor temperature by 16.1 °C, which is promising for next-generation energy-saving buildings.

High stability asymmetric supercapacitor cell developed with novel microwave-synthesized graphene-stabilized ruthenium antimonide nanomaterial

Ruthenium antimony oxide (RuSbO), and ruthenium antimony oxide graphene (RuSbO-G) nanomaterial was synthesized via the microwave-assisted method for the first time and tested as a possible electrode material for an asymmetric supercapacitor device. The formation of the nanocomposites was confirmed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images where the RuSbO material showed randomly distributed spherically shaped nanoparticles, and the RuSbO-G showed ruthenium and antimony nanoparticles scattered randomly on the graphene sheets. The SEM-electron dispersion X-ray spectroscopy (SEM-EDS) showed significant proof for nanoparticle formation with the elemental composition, while the X-ray photoelectron spectroscopy confirmed the oxidation states of the elements present. Both materials were further characterized in a three-electrode cell setup using cyclic voltammetry (CV), galvanostatic charge-discharge (GCD) and electrochemical impedance spectroscopy (EIS) and their electrochemical properties were compared to establish their suitability for energy storage purposes. From the result, different double layer properties were shown by the RuSbO and RuSbO-G in the 1 M Li2SO4 electrolyte. When compared to the RuSbO electrode, the composite had greater energy storage capabilities with a maximum capacitance of 289.47 F g−1 at 0.1 A g−1 current load. An efficiency of ~100 % was reached at a current density of 0.5 A g−1. Subsequently, both materials were used to fabricate a portable asymmetric supercapacitor. The RuSbO-G device yielded a maximum specific capacitance of 167.96 F g−1, resulting in an energy density of 75.58.0 W h kg−1 at a power density of 360 W kg−1 at 0.1 A g−1 current load, with ~100 % charge retention after 4900 cycles. This study turns a new research light on RuSbO based materials as an energy storage material for supercapacitors.

Superflexible hybrid aerogel-based fabrics enable broadband electromagnetic wave management

As problematic interference from electromagnetic waves (EMWs) in modern human life continues to increase, broadband EMW management aerogels have received extensive attention in the safety and thermal management fields, but the mismatch in terms of their mechanical flexibility and functionality has limited their application. This work reports an ultra-lightweight (8.7 mg cm−3), superflexible, hyperelastic (≥95% strain), and superhydrophobic (contact angle: 157°) wearable hybrid aerogel-based fabric that offers both electromagnetic interference (EMI) shielding and infrared (IR) shielding functions. A nanotape-enabled multi-crosslinked hybridization strategy, in which freeze-drying-initiated hydrophobic -Si-O-Si- nanotape welds weak bacterial nanocellulose-silver nanowire interfaces perfectly, gives the fabric outstanding mechanical properties. Optimized synergy gain engineering between the metal and the semiconductor (antimony tin oxide nanoparticles) produces significant enhancements in the electrical conductivity (502.46 S m−1), the EMI shielding effectiveness (SE, 100 dB), and the IR shielding performance (ultralow thermal conductivity of 0.025 W m−1 K−1) of the fabric. The hybrid aerogel-based fabric is fabricated into broadband EMW management clothing, which has excellent prospects for safety and thermal management applications.

Mechanistic Study of the Transition from Antimony Oxide to Antimony Sulfide in the Hydrothermal Process to Obtain Highly Efficient Solar Cells.

Obtaining high-quality absorber layers is a major task for constructing efficient thin-film solar cells. Hydrothermal deposition is considered a promising method for preparing high-quality antimony sulfide (Sb2 S3 ) films for solar cell applications. In the hydrothermal process, the precursor reactants play an important role in controlling the film formation process and thus the film quality. In this study, Sb2 O3 is applied as a new Sb source to replace the traditional antimony potassium tartrate to modulate the growth process of the Sb2 S3 film. The reaction mechanism of the transition from Sb2 O3 to Sb2 S3 in the hydrothermal process is revealed. Through controlling the nucleation and deposition processes, high-quality Sb2 S3 films are prepared with longer carrier lifetimes and lower deep-level defect densities than those prepared from the traditional Sb source of antimony potassium tartrate. Consequently, a solar cell device based on this improved Sb2 S3 delivers a high power conversion efficiency of 6.51 %, which is in the top tier for Sb2 S3 -based solar devices using hydrothermal methods. This research provides a new and competitive Sb source for hydrothermal growth of high-quality antimony chalcogenide films for solar cell applications.

Coaxial Nanofiber IrOx@SbSnOx as an Efficient Electrocatalyst for Proton Exchange Membrane Dehumidifier.

Development of efficient catalysts for oxygen evolution reaction (OER) remains challenging in PEM dehumidifier or vapor electrolyzer. This study developed novel coaxial IrOx@SbSnOx nanofiber (NF) catalysts by electrospinning using a dual-channel needle. This method ensures the fibrous structure and the uniform loading of Ir oxide on the support of antimony tin oxide (ATO). IrO2@SbSnOx nanoparticles were synthesized for comparison. Characterizations showed that the active area and charge transfer resistance of NF was 1.47 times and 17.72% of that of commercial ones, respectively. The overpotential of NF at 10 mA·cm-2 was 359 mV, much smaller than that of commercial IrO2 (418 mV). In addition, the reaction overpotential of NF increased by only 38 mV after 1000 cyclic voltammetry cycles, indicating good electrochemical stability. To explore the enhancement mechanism, first-principles calculations were conducted for theoretically simulating the hetero-structures. Based on d-band theory, the structure formed between ATO and IrO2 can effectively weaken the adsorption of oxygen intermediates on the catalyst surface, which reduces the OER energy barrier from 1.705 to 1.632 eV, causing an over 15% decrease of overpotential after loading on ATO. As a practical attempt, we applied the new catalysts in real PEM assembly for air dehumidification and found that the performance was improved by about 2 times compared with that using commercial catalysts. This study provides a research direction for the design of one-dimensional NF catalysts and their using in PEM applications.

Stable 1T –2H MoS2 heterostructures for efficient electrocatalytic hydrogen evolution

1T-phase molybdenum disulfide (1T MoS2) can efficiently facilitate the charge transfer and provide the active site, exhibiting a better hydrogen evolution reaction (HER) than 2H MoS2. However, its thermodynamic instability becomes a major drawback that hinders its practical application. We report a chemical vapor deposition (CVD) method to grow MoS2 nanosheets with high 1T content (61.5%) by introducing an appropriate amount of antimony oxide. The 1T-2H hybrid structures grown in this mode are thermodynamically stable. 1T phase of the MoS2 produces a unique charge distribution that makes the S atoms at the 1T-2H interface more favorable for H adsorption, thus enhancing the HER activity on the MoS2 basal plane. This study has provided a new idea for the 1T-phase MoS2 preparation for efficient HER.

Synthesis of Ti/SnO<sub>2</sub>-Sb electrode modified by nitrogen and sulfur co-doped graphene for optimization the electrooxidation of neutral red and methyl orange dyes

The degradation of methyl orange (MO) and neutral red (NR) was studied by the direct electrooxidation using nitrogen and sulfur co-doped graphene (NSG) supported antimony doped tin oxide (SnO<sub>2</sub>-Sb). Sol-gel and microwave technics were used to prepare the material (Ti/SnO<sub>2</sub>-Sb-NSG). Raman, XRD, FTIR and TGA/DSC analyses help to confirm the coating of titanium substrate with the SnO<sub>2</sub>-Sb-NSG film. Linear sweet voltammetry results show that Ti/SnO<sub>2</sub>-Sb-NSG material possesses high oxygen overvoltage. Three independent variables including electrolysis time, current density and dye concentration on the performance of the anodic oxidation system was modeled using the Box-Behnken Design. The optimum conditions for MO and NR degradation were for current density 18 mA/cm² and 58 mA/cm², electrolysis time 6 h and 6 h and dye concentration 29 mg/L and 82 mg/L, respectively. However, based on these optimums, MO was degraded at 98.71 % while NR was just degraded at 82.7%. Based on the intermediate compounds, the degradation mechanism of MO at the Ti/SnO<sub>2</sub>-Sb-NSG anode was proposed. Ti/SnO<sub>2</sub>-Sb-NSG electrode showed a higher efficient electrocatalytic performance for NR and MO degradation than that of Ti/Sb-SnO<sub>2</sub> or Ti/Sb-SnO<sub>2</sub>-NG electrodes. Furthermore, the lifetime of Ti/SnO<sub>2</sub>-Sb-NSG was about 31.6 h while Ti/SnO<sub>2</sub>-Sb electrode was 9.0 h.

The size effect on the optical-electrical properties of Cu2S/CdS thin film towards the performance on Ag/p-Cu2S/n-CdS/ATO heterojunction diode

Here we report, room temperature deposition of Cu2S/CdS thin film on antimony doped tin oxide(ATO) substrate through spray pyrolysis and dip coating technique. The effect of size on the deposited Cu2S/CdS thin films and its heterojunction parameters are extensively investigated. The sizes of the thin film are estimated through field-emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) images. The optical properties of the Cu2S/CdS thin film are studied using UV–Vis–NIR spectrometer. It is found that increase in the size, the transmittance decreases, consequently the band-gap energy decreases from 2.92eV to 2.86eV. The refractive index and the dielectric constant are calculated from the optical measurements. In addition, the dispersion of the refractive index is discussed in terms of the Wemple-DiDomenico single-oscillator model. The oscillator parameters such as optical dispersion energies, dielectric constant, the average value of oscillator strength, wavelength of single oscillator, plasma frequency and lattice energy are evaluated. To examine the size-dependent electrical parameters of Cu2S/CdS thin film, high-quality vacuum evaporated silver (Ag) is used as front contact. The current-voltage (I–V) curves of the Ag/p-Cu2S/n-CdS/ATO/glass heterojunction device are measured under dark mode at standard testing conditions (STC). The dark measurements of the fabricated device are investigated through the conventional I–V method, Norde method, and Cheung method. It is observed that the potential height of the heterojunction device decreases from 0.89 to 0.76 with an increment of the size of Cu2S/CdS thin films. It is observed that the size strongly influenced the diode parameters viz. ideality factor, saturation current, barrier height, series, and shunt resistance performance.

Dispersible SnO2 :Sb and TiO2 Nanocrystals After Calcination at High Temperature.

High-temperature treatment of functional nanomaterials, through postsynthesis calcination, often represents an important step to unlock their full potential. However, such calcination steps usually severely limit the preparation of colloidal solutions of the nanoparticles due to the formation of sintered agglomerates. Herein, a simple route is reported to obtain colloidal solutions of calcined n-conductive antimony doped tin oxide (ATO) as well as titanium dioxide (TiO2 ) nanoparticles without the need for additional sacrificial materials. This is achieved by making use of the reduced contact between individual nanoparticles when they are assembled into aerogels. Following the calcination of the aerogels at 500 °C, redispersion of the nanoparticles into stable colloidal solutions with various solvents can be achieved. Although a slight degree of sintering is inevitable, the size of the resulting aggregates in solution is still remarkably small with values below 30nm.

Hybrid additive manufacturing based on vat photopolymerization and laser-activated selective metallization for three-dimensional conformal electronics

Hybrid additive manufacturing technology (HAM) is a great advance of traditional additive manufacturing (AM) processes which enables the direct fabrication of full-functional end-use products rather than individual parts. Three-dimensional (3D) printed electronics is a representative product of HAM that could meet customized functional requirements of the industrial community such as consumer electronics, communication engineering, and automobile and aerospace industries. Herein, we propose a novel HAM technology that combines vat photopolymerization (VPP) 3D printing and the laser-activated electroless plating (ELP) process to fabricate conformal 3D printed electronics. A novel functional liquid photopolymer doped with 3 wt% of antimony tin oxide (ATO) and 1 wt% of titania (TiO2) nanoparticles is developed for this HAM technology. The 3D substrate can be successfully fabricated layer-by-layer with this functional photopolymer by a commercial desktop VPP 3D printer. A near-infrared (NIR) laser system selectively activates the surface of the 3D substrate and induces the SnII seeds for ELP. For 4-hour ELP, the thickness of plated copper layer approaches 11 µm and the electrical conductivity reaches 5.2 × 107 S/m which is close to pure copper (5.8 ×107 S/m). Finally, a selectively copper plated university badge is prepared to demonstrate the fabrication accuracy of the HAM technology, and a 3D conformal light-emitting diode (LED) circuit board is also developed to verify the feasibility of this HAM technology for customizing full-functional electronic products.

Exploring the crystal structure and properties of ytterbium orthoantimonate under high pressure.

The crystal structure of YbSbO4 was determined from powder X-ray diffraction data using the Rietveld method. YbSbO4 is found to be monoclinic and isostructural to α-PrSbO4. We have also tested the influence of pressure on the crystal structure up to 22 GPa by synchrotron powder X-ray diffraction. No phase transition was found. The P-V equation of state and axial compressibilities were determined. Experiments were combined with density-functional theory calculations, which provided information on the elastic constants and the influence of pressure in the crystal structure and Raman/infrared phonons. Results are compared with those from other orthoantimonates. Reasons for the difference in the high-pressure behaviour of YbSbO4 compared with most antimony oxides will be discussed.

Facile engineering 3-D photothermal laser induced graphene for efficient steam generation

Solar driven steam generation is a typical application of solar energy harvesting for clean water production, which has undergone a long-term development. Up to now, a desirable evaporation efficiency has been achieved in lab-scale via advanced materials and structural design However, to maintain a stable performance for long-term practical application, the simplicity of fabrication process, the cost of the raw material and the salt accumulation issue have to be taken into consideration. Here, this research proposed an efficient solar evaporator based on laser induced graphene (LIG) and the commercialized nickel foam. The nickel foam was preferred as the skeleton of the evaporator coupling with hydrophilic polyvinyl alcohol (PVA) to provide sufficient water pathways with reduced water vaporization enthalpy in the bottom layer of the solar evaporator. In addition, plasmonic antimony doped tin oxide (ATO) nanoparticles were introduced into the porous graphene to further enhance the solar absorption and photothermal conversion. Thus, the 3D evaporator exhibits a high evaporation efficiency of 2.21 kg m −2 h −1 in salt water (20 wt% NaCl) under 1 solar irradiation (1 kw m −2 ). Moreover, the evaporator enables a stable evaporation performance upon the saline water during a 120 h test, with no salt crystals accumulated on the surface of evaporator. It is believed that this work presents a potential simple pathway to design and fabricate a portable and efficient evaporator equipped with efficient LIG nanocomposite as an efficient solar absorber. • A novel LIG-ATO nanocomposite has been facilely synthesized vis a one-step laser deposition for a portable solar evaporator.

The role of native point defects and donor impurities in the electrical properties of ZnSb2O4: a hybrid density-functional study.

The ceramic material zinc antimony oxide ZnSb2O4 has promising electrical and magnetic properties, making it suitable for various applications such as electrochemical and energy storage. However, the effects of point defects and impurities on its electrical properties have never been revealed. Here, we employ hybrid density-functional calculations to investigate the energetics and electronic properties of native point defects and donor impurities in ZnSb2O4. The energetically favorable configurations of native point defects under selected growth conditions (O-rich and O-poor) are identified based on the calculated formation energies. The study finds no shallow donor and shallow acceptor defects with low formation energies. Still, the oxygen vacancy (VO) has the lowest formation energy among the donor-type defects under O-rich and O-poor conditions. However, it acts as a very deep acceptor, making it unlikely to provide free electron carriers to the conduction band. Moreover, electron carriers are likely to be compensated by the formation of zinc vacancies (VZn) and the zinc substituted for antimony (ZnSb), which behave as dominant acceptors. Our analysis of the charge neutrality conditions estimates that the Fermi level of undoped ZnSb2O4 would be pinned in a range that is 2.60 eV to 3.12 eV above the VBM for O-rich to O-poor growth conditions, respectively, suggesting that this material is semi-insulating. The possibility of enhancing free electron carriers by doping with Al, Ga, In, and F impurities is also investigated. Our results, however, indicate that high n-type conductivity is hindered by self-compensation in which the impurities additionally act as electron killers. Our results suggest that other impurity candidates and approaches may need to be considered to efficiently dope this material into n-type. Overall, this work paves the way for point defect engineering in this class of ternary oxides.

Microwave synthesis of antimony oxide graphene nanoparticles - a new electrode material for supercapacitors.

For the first time, antimony oxide nanoparticles were produced using a microwave technique and evaluated as a supercapacitor electrode. The specific capacitance derived from the material's galvanostatic charge-discharge curve was 98 F g-1 in 1 M Li2SO4 electrolyte at 0.1 A g-1 current density. The charge storage mechanism visible in the CV curve is nearly rectangular and identical to the EDLC charge storage mechanism. Additionally, antimony species were chemically attached to graphene oxide using an antimony(iii) chloride precursor and subsequently microwave aided procedures were used to convert the antimony species to SbO-G nanocomposites. The results of energy-dispersive X-ray spectroscopy demonstrated the pure character of the produced material. In a three-electrode cell arrangement, the resulting composite was electrochemically characterized. The cyclic voltammogram results showed that among the pristine SbO, graphene, and SbO-G materials, SbO-G had a higher specific capacitance value of 37.58 F g-1, at a scan rate of 10 mV s-1. The material has also demonstrated good conductivity characteristics based on electrochemical impedance spectroscopy research. After 3500 galvanostatic charge-discharge cycles, the material had excellent cycling stability of ∼100%. All the remarkable capacitive properties demonstrated by this material indicate that it can be a viable choice in the field of energy storage devices.

Accessible active sites activated by nano cobalt antimony oxide @ carbon nanotube composite electrocatalyst for highly enhanced hydrogen evolution reaction

The electrochemical hydrogen evolution reaction (HER) was one of new energy development strategies with clean, efficient and renewable characteristics, and electrocatalysts play a crucial role in HER technology. Herein, a composite material (CSO@0.5CNT) derived from the combination of nano cobalt antimony oxide (CSO) with carbon nanotubes (CNT) through hydrothermal reaction, in which the nanoparticles of CSO were closely compounded on the surface of CNT, could be a highly efficient electrocatalyst for HER in 1 M KOH. The binary composite electrocatalyst of CSO and CNT reduced the internal resistance, promoted the charge transfer, exhibited a large electrochemical active area, and obtained the lower overpotential, with 155 mV at 10 mA/cm2 current density. Moreover, such a CSO@0.5CNT electrocatalyst displayed a small Tafel slope of 86.5 mV dec−1, excellent catalytic activity and extraordinary long-term structural stability after 30 h and 3000 CV cycles. Furthermore, the electrocatalytic mechanism revealed by Density Functional Theory (DFT) calculation proved that, the decomposition of H2O molecules was the control step of the whole HER, and the superior electron transport ability of CNT was favorable to the improvement of electrocatalytic performance. Benefitting from accessible active sites on carbon nanotube (C atom) and CSO (Co atom), the composite electrocatalyst of CSO@0.5CNT displayed synergistic effect for electrocatalytic HER properties, and that was the main mechanism for significantly improving the electrocatalytic activities. Our work provides a novel strategy towards high-efficiency electrocatalysts for hydrogen evolution reaction.

Wear Comfort Characteristics of Al2O3/ATO/TiO2-Embedded Multi-Functional PET Fabrics.

The wear comfort of Al2O3/ATO (antimony tin oxide, Sb2SnO5)/TiO2-embedded fabrics was examined in terms of the heat shielding property of ATO particles and emissivity of far-infrared (FIR) radiation according to the sheath/core ratio (wt. %) of Al2O3 and ATO particles embedded in the sheath/core yarns. The thermal radiation of the low-core-ratio (50 wt. %) Al2O3/ATO-embedded fabric was greater than that of the high-core-ratio (70 wt. %) Al2O3/ATO-embedded fabric, which was verified by the higher FIR emissivity. The heat-shielding effect of the ATO particles in the highly Al2O3/ATO-embedded yarns enabled it to shield the FIR emitted from sunlight, resulting in lower emissivity and emissive power of the highly embedded Al2O3/ATO yarn than lower embedded yarn. Accordingly, lower Al2O3/ATO-embedded yarns are required to obtain excellent thermal radiation of the fabrics. The fabric with a low core ratio (50 wt. %) exhibited superior moisture absorption, fast-drying properties, and a higher heat retention rate than fabrics with a high core ratio (70 wt. %). Furthermore, the fabric with a low core ratio exhibited superior breathability to the fabric with a high core ratio, resulting in easy moisture vapor permeability. These findings show that the fabric with a low core ratio (50%) of Al2O3/ATO particles imparts superior absorption, moisture vapor permeability, and thermal wear comfort to the high-core-ratio fabric (70%), giving it a comfortable wear-comfort feel while wearing the clothing. Hence, low-core-ratio yarn is suitable for warm-up fabric with UV-protection and anti-static characteristics.

Light-enhanced transparent hydrogel for uric acid and glucose detection by four different analytical platforms

The lack of solid-phase media limits the portability of colorimetric sensing platforms. In this study, a series of transparent polyvinyl alcohol (PVA) hydrogels encapsulated antimony tin oxide nanoparticles (ATO NPs) and 3,3′,5,5′-tetramethylbenzidine (TMB) were developed as the solid-phase sensing media for glucose and uric acid. Under the conditions of H2O2 and UV light, the hydrogel presented a multicatalytic ability (photo Fenton-like and peroxidase-like activities), which accelerated the oxidation of TMB, turning the hydrogel from colorless to blue and finally enhancing the detection signal. The plasticity of the hydrogel allowed it to be designed into various shapes (membrane, microsphere etc.) to adapt multiple detection platforms (a liquid/solid-phase UV spectrophotometer, a NanoPhotometer, and smartphone spectroscopy). The hydrogel sensing media exhibited excellent tunability and enhanced the photocatalytic ability. The proposed material was successfully applied to detect glucose and uric acids in real samples by four detection platforms to evaluate its practicability.

Stoichiometric metal nitration based novel green synthesis of mesoporous metal oxides and their enhanced heterogeneity

In this work, a general and novel method for the green synthesis of mesoporous metal oxides via stoichiometric metal nitration has been demonstrated. Pluronic surfactants and their effect on synthesis procedures in terms of surface area have been experimentally studied in detail. Contrary to the traditional synthesis procedure, water has been utilized as the solvent and in several cases, such as tin oxide, manganese oxide, aluminum oxide, antimony oxide, zinc oxide, cobalt oxide, copper oxide, yttrium oxide, lanthanum oxide, and silver either the highest or comparable surface areas have been successfully synthesized. Through XRD, and TEM, all materials were observed to be crystalline except silver and magnesium oxide. SEM shows that with an increase in surfactant molar mass agglomeration decreases. Ammonia chemisorption on acidic materials gives quantitative amounts of ammonia chemical bonding with catalysts, whereas carbon dioxide chemisorption gives a quantitative value of CO2 chemical binding with basic sites. As high as 1901.8 μmol/g and 994.6 μmol/g ammonia chemisorption values for oxides of vanadium and tin were achieved. Amphoteric materials give both acidic and basic enhanced adsorption. Finally, all synthesized materials are studied under organic catalytic transformations. Benzyl bromide is theoretically more active compared with benzylamine and benzyl alcohol which was also experimentally shown through the conversion.

Preparation and thermal characterization of capric-myristic acid binary eutectic mixture with silver–antimony tin oxide and silver-graphane nanoplatelets hybrid-nanoparticles as phase change material for building applications

• Capric–Myristic acid (CA-MA) binary mixture is proposed for building applications. • Silver- Graphene nanoplatelets (Ag-GNP) (1% wt) was used as hybrid nanocomposites. • Melting and freezing temperature of CA-MA/ Ag-GNP (1% wt) are 18.7 °C and 15.7 °C. • The thermal conductivity of CA-MA/ Ag-GNP (1% wt) was enhanced by 18.52 %. • The prepared CA–MA/Ag-GNP (1% wt) mixture are suitable for building applications. The capric-myristic acid binary eutectic mixture (CA-MA) was prepared as phase change material (PCM) for building applications; later, novel hybrid-nanocomposites of silver–antimony tin oxide (Ag-ATO) and silver-graphane nanoplatelets (Ag-GNP) were added with CA-MA with a weight percentage of 1 and 2 respectively to form a hybrid-nanocomposite PCMs (HNCPCMs). The chemical and thermal characterization of pure CA-MA and HNCPCMs showed that their stability is significant for building applications. The melting temperature (T m ) and freezing temperature (T f ) of pure CA-MA synthesised are 18.15 °C and 16.00 °C, respectively, with melting latent heat (H m ) and freezing latent heat (H f ) of 158.75 J/g and 158.07 J/g, respectively. An HNCPCM of CA-MA/Ag-GNP (1 % wt) shows an improved melting thermal conductivity of 18.52 %, with negligible deviation in melting-freezing temperature and latent heat. The proposed CA-MA/Ag-GNP (1% wt) has significant thermal, chemical, and long-term cycling reliability, making it a promising material for building applications.

Construction of Highly Efficient Zn0.4Cd0.6S and Cobalt Antimony Oxide Heterojunction Composites for Visible-Light-Driven Photocatalytic Hydrogen Evolution and Pollutant Degradation

Photocatalytic technology could effectively degrade pollutants and release hydrogen. Herein, novel composite materials of Zn0.4Cd0.6S (ZCS) and cobalt antimony oxide (CSO) with different proportions were successfully synthesized through a hydrothermal reaction process. It was proved via various characterization analyses that abundant nano ZCS particles (about 100 nm) were closely coated on the surface of larger CSO particles in the composite photocatalysts, and the heterojunction structure was formed. The synthesized materials could be used as highly efficient photocatalysts to boost the photocatalytic hydrogen evolution and degradation of methylene blue (MB) in visible light. The composite photocatalysts displayed favorable stability, and the optimal proportion was ZCS/1CSO. In addition, the composite materials exhibited a wider absorption range for visible light, and the apparent hydrogen production rate was about 3.087 mmol·g−1·h−1. Meanwhile, compared with single materials, the composite photocatalyst obtained higher photocurrent response and lower electrochemical impedance through conducting photo-electrochemical experiments and analysis. Moreover, all of the photo-generated electrons, superoxide radicals, photo-generated holes, and hydroxyl radicals were proved to contribute the MB photodegradation and hydrogen evolution, and the former two active species played more vital roles. Furthermore, the effective separation of photo-generated electrons and holes through the n-type of ZCS and p-type of CSO heterojunction structure accelerated the improvement of photocatalytic abilities for composite materials. The photo-generated electrons concentrated in the conduction band of ZCS might be helpful for the improvement of hydrogen evolution abilities of composite photocatalysts. This work not only provides a novel strategy towards high-efficiency composite photocatalysts through constructing heterojunction assisted with hydrothermal reaction, but also demonstrates the possibility of utilizing binary composites for enhanced hydrogen evolution reaction and pollutant degradation.