Search Results (239)

Tungsten oxide (WO₃) nanostructures have emerged as promising electroactive materials due to their high pseudocapacitance, structural versatility, and chemical stability, while reduced graphene oxide (rGO) provides excellent electrical conductivity and surface area. The strategic combination of these nanomaterials in hybrid electrodes has gained attention for enhancing the energy storage performance of supercapacitors. In this work, we report the fabrication and electrochemical performance of nanostructured multilayer films based on the electrostatic Layer-by-Layer (LbL) self-assembly of poly (amidoamine) (PAMAM) dendrimers alternated with tungsten oxide (WO₃) nanofibers dispersed in reduced graphene oxide (rGO). The films were deposited onto indium tin oxide (ITO) substrates and subsequently subjected to electrochemical reduction. UV-Vis spectroscopy confirmed the linear growth of the multilayers, while atomic force microscopy (AFM) revealed homogeneous surface morphology and thickness control. Electrochemical characterization by cyclic voltammetry (CV) and galvanostatic charge–discharge (GCD) revealed a predominantly electrical double-layer capacitive (EDLC) behavior. From the GCD measurements (PAMAM/rGO-WO₃)₂₀ films achieved an areal capacitance of ≈2.20 mF·cm⁻², delivering an areal energy density of ≈0.17 µWh·cm⁻² and an areal power density of ≈2.10 µW·cm⁻², demonstrating efficient charge storage in an ultrathin electrode architecture. These results show that the synergistic integration of PAMAM dendrimers, reduced graphene oxide, and WO₃ nanofibers yields a promising strategy for designing high-performance electrode materials for next-generation supercapacitors. Full article

The development of hydrogen energy is advancing rapidly, while the progress of hydrogen sensors has been relatively lagging behind and cannot meet the stringent performance requirements of hydrogen energy applications. WO₃ has attracted significant attention due to its highly complementary optical and electrical responses to hydrogen. In this study, hydrogen-sensitive WO₃ thin films characterized by vertically aligned crystallites were fabricated by modulating the substrate temperature and oxygen pressure during pulsed laser deposition. Building upon this foundation, a comprehensive investigation into surface modification strategies for enhancing sensitivity was undertaken. The surface modifications encompassed eight distinct metals and four different metal oxides. Among the metal-modified samples, palladium (Pd) Pd exhibited a markedly enhanced electrical response, defined as the ratio of the resistance in hydrogen-free air to that in hydrogen, of 1022, corresponding to ~45 times higher than the value of 22.4 achieved for Pt-modified films and 120 times higher than the value of 8.4 for Au-modified films. In addition, Pd/WO₃ films showed a measurable optical transmittance change of 9.7%, while all other metal-modified samples exhibited negligible optical responses (<1%). This enhancement is attributable to the catalytic and electronic sensitisation effects of Pd. Conversely, metals such as platinum (Pt), gold (Au), and silver (Ag) elicited negligible optical responses, suggesting minimal catalytic activity. The electrical response in these cases was primarily governed by electronic sensitization effects related to the work function of the metal, with higher work function values correlating with more pronounced sensitization. Regarding metal oxide modifications, the sensitization effect was more substantial when the disparity in work function between the oxide and WO₃ was greater, and this enhancement was found to be independent of the charge carrier type of the modifying oxide. These results offer significant insights into the design principles underlying high-performance WO₃-based hydrogen sensors and underscore the pivotal influence of surface modification in governing their sensing characteristics. Full article

Tungsten trioxide (WO₃) exhibits complementary optical and electrical responses toward hydrogen, yet the interplay between interfacial stress, crystal phase stabilization, and gasochromic/chemiresistive performance remains insufficiently understood. In this work, WO₃ films were grown on four single-crystal oxide substrates to systematically tune interfacial stress and thereby modulate the resulting crystal phase, microstructure, and exposed facets. θ–2θ diffraction revealed that WO₃ adopts a monoclinic phase on YAlO₃ and SrLaAlO₄, whereas a high-temperature orthorhombic phase is stabilized on LaAlO₃ (LAO) and SrTiO₃ due to stronger interfacial constraint. Compared with the amorphous quartz reference, the single-crystal substrates significantly enhanced both gasochromic and chemiresistive responses. In particular, the orthorhombic WO₃/LAO film exhibited an electrical response of 1.97 × 10⁴ (R_air/R_H2), an optical transmittance changed of 12.7%, and an electrical response time of 1 s toward 2% H₂ at 80 °C, far exceeding the monoclinic and amorphous counterparts. The combined effects of stress-induced phase stabilization, film orientation, and hydrogen diffusion pathways are shown to govern the non-monotonic sensing trends among different substrates. These findings elucidate the structural origin of hydrogen sensitivity in WO₃ and provide guidance for stress-engineered design of high-performance gasochromic and chemiresistive sensors. Full article

With continuous breakthroughs in electrochromic technology, tungsten trioxide (WO₃) thin films, as a core material in this field, are rapidly expanding their applications in smart windows, anti-glare automotive rearview mirrors, and adaptive optical lenses. Owing to its excellent electrochromic properties—including high optical modulation, short switching times, and high coloration efficiency—WO₃ has become a research focus in the field of electrochromic devices. This review takes WO₃ thin films as the research subject. It begins by introducing the crystal structure of WO₃ and the ion/electron co-intercalation-based electrochromic mechanism and explains two key performance parameters for evaluating electrochromic properties: optical modulation amplitude and coloration efficiency. Subsequently, it provides a detailed review of recent advances in the preparation of WO₃ thin films via physical methods (including sputtering deposition, evaporative deposition, and pulsed laser deposition) and chemical methods (including hydrothermal, sol–gel, and electrodeposition methods). A systematic comparison is made of the microstructure and electrochromic performance (optical modulation amplitude and coloration efficiency) of films prepared by different methods, and the interaction between WO₃ film morphology and device structure is analyzed. Finally, the advantages and challenges of physical and chemical methods in tuning film properties are summarized, and the outlook of their application prospects in high-performance electrochromic devices is given. This review aims to provide guidance for the selection and process optimization of WO₃ thin films with enhanced performance for applications such as smart windows, anti-glare rearview mirrors, and adaptive optical systems. Full article

Per- and polyfluoroalkyl substances (PFASs) have attracted global attention due to their persistence and biological toxicity, becoming critical emerging contaminants in river and lake environments worldwide. Building upon existing studies, this work aims to comprehensively understand the pollution patterns, environmental behaviors, and potential risks of PFASs in freshwater systems, thereby providing scientific evidence and technical support for precise pollution control, risk prevention, and the protection of aquatic ecosystems and human health. Based on publications from 2002 to 2025 indexed in the Web of Science (WoS), bibliometric analysis was used to explore the temporal evolution and research hotspots of PFASs, and to systematically review their input pathways, pollution characteristics, environmental behaviors, influencing factors, and ecological and health risks in river and lake environments. Results show that PFAS inputs originate from both direct and indirect pathways. Direct emissions mainly stem from industrial production, consumer product use, and waste disposal, while indirect emissions arise from precursor transformation, secondary releases from wastewater treatment plants (WWTPs), and long-range atmospheric transport (LRAT). Affected by source distribution, physicochemical properties, and environmental conditions, PFASs display pronounced spatial variability among environmental media. Their partitioning, degradation, and migration are jointly controlled by molecular properties, aquatic physicochemical conditions, and interactions with dissolved organic matter (DOM). Current risk assessments indicate that PFASs generally pose low risks in non-industrial areas, yet elevated ecological and health risks persist in industrial clusters and regions with intensive aqueous film-forming foam (AFFF) use. Quantitative evaluation of mixture toxicity and chronic low-dose exposure risks remains insufficient and warrants further investigation. This study reveals the complex, dynamic environmental behaviors of PFASs in river and lake systems. Considering the interactions between PFASs and coexisting components, future research should emphasize mechanisms, key influencing factors, and synergistic control strategies under multi-media co-pollution. Developing quantitative risk assessment frameworks capable of characterizing integrated mixture toxicity will provide a scientific basis for the precise identification and effective management of PFAS pollution in aquatic environments. Full article

CuWO₄ films were prepared on FTO glass substrates by the hydrothermal method. To improve their photocatalytic activity, the CuWO₄ films were further modified with BiOI using the successive ionic layer adsorption and reaction (SILAR) method. Characterization results indicate that BiOI and CuWO₄ achieved nanoscale mixing and formed a Type II p-n heterojunction. The heterojunction formation not only extends the light absorption threshold of CuWO₄ from 530 nm to 660 nm but also enhances the light absorption capacity across the entire solar spectrum. More importantly, the heterojunction formation facilitates the separation and transfer of photogenerated carriers and inhibits the recombination of photogenerated electrons and holes, which is evidenced by the results of PL spectra, photocurrent density, and EIS spectra. Compared with individual CuWO₄ films, the photocatalytic activity of BiOI/CuWO₄ heterojunction films in degrading the organic dye MB is increased by up to 1.17 times. Additionally, BiOI/CuWO₄ heterojunction films exhibit certain activity in the photocatalytic degradation of polystyrene (PS) nanoplastics and are capable of reducing the average particle size of nanoplastics from 425 nm to 325 nm within 80 h. Full article

The photocatalytic efficiency of TiO₂ was significantly enhanced by coupling with WO₃ to form a TiO₂/WO₃ heterostructure, designed to operate effectively under UV-LED irradiation. The nanocomposites were synthesized via a hydrothermal route, and their activity was evaluated through the degradation of the pharmaceutical pollutant venlafaxine. Contaminants are rarely addressed in photocatalytic studies. Unlike a simple physical mixture of commercial TiO₂ and WO₃ powders, the hydrothermally synthesized TiO₂/WO₃ photocatalyst exhibited superior efficiency, attributable to its nanoscale dimensions achieved via the hydrothermal route, which promoted improved charge carrier separation, enhanced surface homogeneity, and the formation of an effective heterojunction interface. An optimization study varying the WO₃ content (5, 10, 20, and 30 wt.%) within the TiO₂ revealed that the 10 wt.% WO₃ composition achieved the highest performance, with ~52% venlafaxine degradation within 60 min. SEM, TEM, FTIR, Raman spectroscopy, XRD, and UV-Vis DRS revealed the successful incorporation of WO3 into the TiO₂ matrix, confirming phase purity and composition-dependent structural evolution of the nanocomposite, and evidencing extended light absorption and superior charge-transfer properties. Importantly, the optimized photocatalyst thin film retained excellent stability and reusability, maintaining high degradation efficiency over three consecutive cycles with negligible activity loss, which avoids slurry separation. These findings establish hydrothermally synthesized TiO₂/10%WO₃ thin film heterostructures as effective and sustainable photocatalytic platforms for the removal of pharmaceutical pollutants in wastewater under UV-LED irradiation. Full article

In this study, high-conductivity W-doped Ga₂O₃ thin films were successfully fabricated by directly depositing a composition of Ga₂O₃ with 10.7 at% WO₃ (W:Ga = 12:100) using electron beam evaporation. The resulting thin films were found to be amorphous. Due to the ohmic contact behavior observed between the W-doped Ga₂O₃ film and platinum (Pt), Pt was used as the contact electrode. Current-voltage (J-V) measurements of the W-doped Ga₂O₃ thin films demonstrated that the samples exhibited significant current density even without any post-deposition annealing treatment. To further validate the excellent charge transport characteristics, Hall effect measurements were conducted. Compared to undoped Ga₂O₃ thin films, which showed non-conductive characteristics, the W-doped thin films showed an increased carrier concentration and enhanced electron mobility, along with a substantial decrease in resistivity. The measured Hall coefficient of the W-doped Ga₂O₃ thin films was negative, indicating that these thin films were n-type semiconductors. Energy-Dispersive X-ray Spectroscopy was employed to verify the elemental ratios of Ga, O, and W in the W-doped Ga₂O₃ thin films, while X-ray photoelectron spectroscopy analysis further confirmed these ratios and demonstrated their variation with the depth of the deposited thin films. Furthermore, the W-doped Ga₂O₃ thin films were deposited onto both p-type and heavily doped p⁺-type silicon (Si) substrates to fabricate heterojunction diodes. All resulting devices exhibited good rectifying behavior, highlighting the promising potential of W-doped Ga₂O₃ thin films for use in rectifying electronic components. Full article

Binary oxide ceramics have emerged as key materials in solar energy research due to their versatility, chemical stability, and tunable electronic properties. This study presents a comparative analysis of seven prominent oxides (TiO₂, ZnO, Al₂O₃, SiO₂, CeO₂, Fe₂O₃, and WO₃), focusing on their functional roles in silicon, perovskite, dye-sensitized, and thin-film solar cells. A bibliometric analysis covering over 50,000 publications highlights TiO₂ and ZnO as the most widely studied materials, serving as electron transport layers, antireflective coatings, and buffer layers. Al₂O₃ and SiO₂ demonstrate highly specialized applications in surface passivation and interface engineering, while CeO₂ offers UV-blocking capability and Fe₂O₃ shows potential as an absorber material in photoelectrochemical systems. WO₃ is noted for its multifunctionality and suitability for scalable, high-rate processing. Together, these findings suggest that binary oxide ceramics are poised to transition from supporting roles to essential components of stable, efficient, and environmentally safer next-generation solar cells. Full article

Nosocomial infections caused by Candida albicans pose serious challenges to healthcare systems due to their persistence on medical surfaces and resistance to conventional disinfectants. This study evaluates antifungal properties of SnO₂ doped with silver and cuprite nanoparticles and WO₃ thin films, as well as cobalt (CoFe₂O₄) and cobalt–nickel (Co_0.5Ni₀.₅Fe₂O₄) ferrite nanoparticles, activated by ultraviolet C (UVC) radiation, direct electric current (up to 100 V), and magnetic fields. SnO₂ films were synthesized by Spray Pyrolysis and WO₃ by Sputtering deposition, Ferrites nanoparticles by sol–gel, while metallic nanoparticles were synthetized via chemical reduction. Characterization consisted mainly of SEM, TEM, and XRD, and their antimicrobial activity was tested against C. albicans. WO₃ films achieved 86.2% fungal inhibition after 5 min of UVC exposure. SnO₂ films doped with nanoparticles reached 100% inhibition when combined with UVC and 100 V. Ferrite nanoparticles alone showed moderate activity (21.9%–40.4%) but exhibited strong surface adhesion to fungal cells, indicating potential for magnetically guided antifungal therapies. These results demonstrate the feasibility of using multifunctional nanomaterials for rapid, non-chemical disinfection. The materials are low-cost, scalable, and adaptable to hospital settings, making them promising candidates for reducing healthcare-associated fungal infections through advanced surface sterilization technologies. Full article

The poor selectivity of metal oxide semiconductor sensors is a major constraint to their application in the detection of chemical warfare agents. We prepared a (Pt+Pd+Rh)@Al₂O₃/(Pt+Rh)-WO₃ sensor by using (Pt+Pd+Rh)@Al₂O₃ as a catalytic film material and (Pt+Rh)-WO₃ as a gas-sensitive film material. Using temperature dynamic modulation, the (Pt+Pd+Rh)@Al₂O₃/(Pt+Rh)-WO₃ sensor was realised to improve the selectivity for mustard. Due to the catalytic effect of the (Pt+Pd+Rh)@Al₂O₃ catalytic film on mustard, mustard was able to be catalytically generated into mustard sulphoxide after passing through the (Pt+Pd+Rh)@Al₂O₃ catalytic film. Under a certain temperature dynamic modulation, the mustard concentration on the surface of the (Pt+Rh)-WO₃ gas-sensitive film showed an increase and then a decrease. Since the resistance response of the (Pt+Rh)-WO₃ gas-sensitive film to mustard was much higher than that of mustard sulphoxide, the change in the resistance of the (Pt+Rh)-WO₃ gas-sensitive film was mainly determined by the change in the concentration of mustard, which led to the peak signal in the curve of its resistance response to mustard. The experimental results showed that the (Pt+Pd+Rh)@Al₂O₃/(Pt+Rh)-WO₃ sensor had peak signals in the resistance response to mustard only, and not in the resistance response to 12 interfering gases, such as carbon monoxide. Full article

Electrochromic devices have garnered significant interest owing to their promising applications in smart multifunctional electrochromic energy storage systems (EESDs) and their emerging next-generation electronic technologies. Tungsten oxide (WO₃), possessing both electrochromic and pseudocapacitive characteristics, offers great potential for developing multifunctional devices with enhanced performance. However, achieving an efficient and straightforward synthesis of WO₃ electrochromic films, while simultaneously ensuring high coloration efficiency and energy storage capability, remains a significant challenge. In this work, a low-temperature hydrothermal approach is employed to directly grow hexagonal-phase WO₃ films on FTO substrates. This process utilizes sorbitol to promote nucleation and rubidium sulfate to regulate crystal growth, enabling a one-step in situ fabrication strategy. To complement the high-performance WO₃ cathode, a composite PB/SnO₂ film was designed as the anode, offering improved electrochromic properties and enhanced stability. The assembled EESD exhibited fast bleaching/coloration response and a high coloration efficiency of 101.2 cm² C⁻¹. Furthermore, it exhibited a clear and reversible change in optical properties, shifting from a transparent state to a deep blue color, with a transmittance modulation reaching 81.47%. Full article

This study develops novel superhydrophobic UHMWPE/PTFE/PVA composites via hot-pressing sintering to achieve ultra-low friction and enhanced wear resistance. The ternary system synergistically combines UHMWPE’s mechanical stability, PTFE’s lubricity, and PVA’s dispersion/binding capability. Results show PTFE disrupts UHMWPE crystallization, reducing melting temperature by 2.77 °C and enabling energy dissipation. All composites exhibit hydrophobicity, with optimal formulations (UPP3/UPP4) reaching superhydrophobicity. Tribological testing under varied loads and frequencies reveals low friction, where UPP1 achieves a COF of 0.043 and wear rate below 1.5 × 10⁻⁵ mm³/(N·m) under low-load conditions. UHMWPE oxidative degradation forming carboxylic acids at the interface (C=O at 289 eV, C–O at 286 eV). Formation of tungsten oxides (WO₃/WO₂), carbides (WC), and transfer films on steel counterparts. A four-step tribochemical reaction pathway is established. PVA promotes uniform transfer films, while PTFE lamellar peeling and UHMWPE chain stability enable sustained lubrication. Carbon-rich stratified accumulations under high-load/speed increase COF via abrasive effects. The composites demonstrate exceptional biocompatibility and provide a scalable solution for biomedical and industrial tribological applications. Full article

Investigations of the synthesis of multicomponent coatings and their subsequent application to metal substrates to increase the wear resistance of materials is relevant for industry. Nickel compounds obtained from oxidized magnesia-iron nickel ores with a desorption rate of more than 94% were used to create Ni-MoO₃-WO₃ electroplating. Such composite samples formed from an aqueous alcohol solution reduced the content of sodium and ammonium chlorides. The annealing and dehydration of samples at a temperature of 725 °C in an air atmosphere made it possible to achieve the highest level of crystallinity. In this case, an isomorphic substitution of W atoms by Mo occurs, which is confirmed by electron paramagnetic resonance (EPR) spectroscopy studies. The invariance of the shape of the EPR spectrum with a sequential increase in microwave radiation power revealed the stability of the bonds between the particles. The surface morphology of Ni-MoO₃-WO₃ films deposited on an Al substrate is smooth and has low roughness. In this case, an increased degree of wear resistance has been achieved. Thus, a recipe for the formation of an electroplating with stable bonds between the components and increased wear resistance was obtained. Full article

Quickly detecting hydrogen leakage is crucial to provide early warning for taking emergency measures to avoid personnel casualties and explosion accidents in hydrogen energy fields. Here, a compact optical fiber hydrogen sensing system with high sensitivity and quick response rate is proposed in this work. A laser diode (LD) and two photodetectors (PD) are employed as light source and optical signal transformation devices, respectively. This sensing system employs single-mode optical fiber deposited with WO₃-PdPt-Pt nanocomposite film system as sensing element. Under irrigating power of 6 mW, the sensing probe exhibits an ultra-fast response to hydrogen concentrations of 4000 ppm and 10,000 ppm, with response times of 0.44 s and 0.34 s, respectively. In addition, detection limit of 3 ppm can be achieved by using this sensing system. The sensor also shows good repeatability during hydrogen exposure of 3~10,000 ppm, demonstrating its great potential application for hydrogen leakage in hydrogen energy facilities. Full article