- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Electrochromic device with Magnetron sputtered Tungsten Oxide (WO<sub>3</sub>) and nafion membrane: performance with varying Tungsten Oxide thickness- A report
摘要： Electrochromics is the emerging technology for energy conservation and indoor climatic control through smart windows. In this study we are reporting four layer electrochromic device: ITO (400nm)/ commercially procured Nafion (183μm) / WO3 (44nm to 200nm)/ ITO (400nm). The active area (A) of the electrochromic devices are 3cm2. The tungsten oxide (WO3) and ITO thin films have been deposited at room temperature (300 K) by reactive DC Magnetron sputtering. The sheet resistance of ITO is 20 ?/□. The “as deposited” WO3 films are amorphous and have high optical transmission (75%- 85%) in the visible spectrum. The optical band gap decreases with increasing thickness of WO3 thin films. The coloration efficiency (CE) of the electrochromic device increases with increasing thickness of the WO3 layer. The CE for the device with WO3 thickness 200 nm is 184 cm2/C: the highest reported so far for a hybrid electrochromic device. The increase in the CE with thickness has been explained (for the first time) by replacing the surface charge density (Q/A) with the volume charge density (Q/A*t) in the coloration efficiency formula derived from the Beer Lambert’s law.
关键词： coloration efficiency,electrochromism,nafion and Magnetron sputtering.,Tungsten oxide
更新于2025-11-19 16:56:35
-
Visible-Light Overall Water Splitting by CdS/WO <sub/>3</sub> /CdWO <sub/>4</sub> Tricomposite Photocatalyst Suppressing Photocorrosion
摘要： Photocatalytic water splitting under visible light has attracted attention as a possible solution to the energy exhaustion problem. Hitherto, water splitting has been generally achieved using several oxynitrides, oxysul?des, and nitrides, and only a few studies report water splitting using cadmium sul?de (CdS) as a photocatalyst. A major reason for this is that CdS undergoes photocorrosion. In this study, we achieved an overall water splitting under visible light using a CdS/WO3/CdWO4 tricomposite photocatalyst. In the process, photocorrosion of CdS was suppressed by covering it with WO3 and CdWO4, and the oxidation reaction progressed in WO3 by the Z-scheme type photocatalytic reaction.
关键词： cadmium tungstate,tungsten oxide,photocorrosion,water splitting,cadmium sul?de,Z-scheme
更新于2025-11-19 16:51:07
-
A Comparative Study of Gas Sensing Properties of Tungsten Oxide, Tin Oxide and Tin-Doped Tungsten Oxide Thin Films for Acetone Gas Detection
摘要： Nowadays, various metal oxide thin films have been used for the purpose of gas sensing. This research depicts a comparison of gas sensing properties among four different metal oxide thin films, namely, tungsten dioxide (WO2), tungsten trioxide (WO3), tin oxide (SnO2) and tin doped tungsten trioxide (Sn-doped WO3), for detecting acetone gas. Each metal oxide thin film was subjected to acetone gas flow of various concentrations and the corresponding changes in resistance were calculated. Characterizations such as x-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), and gas sensing characterization for recording resistance changes have been performed. Each film was annealed at different temperatures for 1 h (WO2 and WO3 at 500°C, SnO2 at 300°C and Sn-doped WO3 at 400°C) so as to achieve an optimum grain size for sensing. The XRD patterns reveal formation of an orthorhombic phase of WO2, hexagonal phase of WO3 and orthorhombic phase of SnO2. AFM and SEM depict clear images of grain boundaries on the film. SnO2 has been found to be the best thin film for sensing acetone gas. Operational optimum temperature for sensing acetone gas has been calculated for each thin film (260°C for WO2, 220°C for WO3, 360°C for SnO2 and 300°C for Sn-doped WO3). It can detect a very low concentration of 1.5 ppm acetone gas with a good resistance response change of 30%. Various concentrations of acetone gas, namely, 1.5 ppm, 3 ppm, 5 ppm, 7 ppm, 10 ppm, 15 ppm and 20 ppm, have been detected using these metal oxide thin films, and thus the comparison has been made. The response time for SnO2 is approximately 3 min and recovery time is approximately 4 min.
关键词： tungsten oxide,acetone gas detection,topography,tin oxide,Metal oxide thin films,surface metrology,gas sensing,tin-doped tungsten oxide
更新于2025-09-23 15:23:52
-
Two-dimensional amorphous heterostructures of Ag/a-WO3- for high-efficiency photocatalytic performance
摘要： Synergistic photocatalysis is an important concept for designing the high-efficiency catalysis for fundamental research and technical applications. In this study a well-defined synergistic photocatalysis system is realized by the 2D amorphous heterostructures (2DAHs) Ag/a-WO3-x, which are constructed by Ag nanoparticles on 2D amorphous tungsten oxide (a-WO3-x) fabricated via supercritical CO2 method. We demonstrate theoretically that the oxygen evolution reactions (OER), characterized by photocurrent response, have been dramatically improved in Ag/a-WO3-x than those of both single a-WO3-x and Ag/WO3 systems. Such an enhanced photoelectrochemical performance attributes to the superposition effect of amorphous effect catalysis and local surface plasmon resonances (LSPR) catalysis. More interestingly, the ab initio density-functional theory calculations reveal that the amorphous effect catalysis ascribes to the unique d-d tail states coupling of both Ag and W atoms in the 2DAHs. Overall, our findings not only propose the prototype of synergistic photocatalysis, but also provide a new methodology to the design of novel catalyst.
关键词： 2D amorphous tungsten oxide,amorphous effect catalysis,synergistic photocatalysis,d-d tail states coupling,2D amorphous heterostructures Ag/a-WO3-x
更新于2025-09-23 15:23:52
-
The design of a polyaniline-decorated three dimensional W18O49 composite for full solar spectrum light driven photocatalytic removal of aqueous nitrite with high N2 selectivity
摘要： Photocatalysis using solar energy is the most promising green technology for nitrite removal. However, effective photocatalytic performance is often challenged by the limited light absorption, utilization of expensive noble metals and undesired products (nitrate and ammonium). Here, we report for the first time that a full solar light response polyaniline-decorated three dimensional W18O49 composite (PANI@W18O49), a noble metal-free photocatalyst, possesses excellent photocatalytic activity for aqueous nitrite removal with high N2 selectivity. The prepared sample was thoroughly identified via XRD, Raman, FTIR, SEM, TEM, UV–vis DRS and PL. The catalytic results demonstrated that over 80% N2 selectivity (initial concentration 1.0 mM) was achieved through the PANI@W18O49 without sacrificial agent under 300 W Xe lamp irradiation for 60 min. Such advantages were attributed to the built-in junction between n-type W18O49 and p-type PANI, offering suitable redox levels of electron-hole pairs for NO2? reaction. The modification of PANI also benefited the light harvesting ability and activated carriers migration, the calculated rate constant of PANI@W18O49 is about four times as high as that of W18O49. The current study not only prepared a promising photocatalyst, but also provides new insights into improving the photocatalytic activity and N2 selectivity for nitrite treatment.
关键词： Nitrite,Polyaniline,Tungsten oxide,Full solar spectrum light driven,Photocatalysis
更新于2025-09-23 15:23:52
-
A novel approach to synthesize nanostructured WO3 and graphene/WO3 nanocomposites: Structural and morphological investigations
摘要： Nanostructured metal oxide based nanocomposites have attracted considerable attention due to their promising and remarkable properties. In the present study, a novel method is developed for the preparation of Graphene oxide (GO)/tungsten oxide WO3 nanocomposites by using tungsten carbide (WC) and graphite as precursors. (GO)/WO3 nanocomposites are prepared via in situ and ex situ chemical approaches followed by subsequent thermal treatment at 500 °C. The obtained samples were characterized by di?erent techniques to con?rm the transformation of WC to WO3 nanostructures and the formation of their nanocomposites with carbon nanostructures. X-ray di?raction (XRD) analysis indicates that the WO3 nanoparticles were ?ne crystallized with a monoclinic phase even after interaction with GO for the ex situ prepared GO/WO3 and di?erent phases of WO3 appeared during their growth in situ in the presence of graphite. Scanning electron microscopy (SEM) images reveal the rods-like shape of WO3 nanostructures with uniform distribution onto the RGO nanosheets. Fourier transform infrared (FTIR) spectroscopy con?rms the interaction and charge transfer between the components. The experimental results reveal the e?ciency of the proposed approach that opens up a promising route to prepare G/WO3 nanocomposites for many applications.
关键词： Graphene,Hybrid nanocomposite,Tungsten oxide
更新于2025-09-23 15:23:52
-
A promising CuOx/WO3 p-n heterojunction thin-film photocathode fabricated by magnetron reactive sputtering
摘要： A CuOx/WO3 thin-film based on p-n heterojunction proposed as a highly performance and stable photocathode. The CuOx/WO3 thin-film was deposited by magnetron reactive sputtering layer by layer, followed with slow rate annealing in O2 ambient. This is an excellent method for high-quality and uniform composite thin-film deposition with large areas at a high growth rate. The optimized CuOx/WO3 thin-film photocathode after slow rate annealing at 500 °C in O2 provides an obviously enhanced photoinduced current density of -3.8 mA cm-2 at a bias potential of -0.5 V (vs. Ag/AgCl), which value is 1.5 times higher than that of bared CuOx thin-film. This highly enhanced photoelectrochemical performance is attributed to p-n heterojunction, which accelerates the photogenerated electrons and holes transfer to n-WO3 and p-CuOx, thereby accelerate the separation of photogenerated carries. In addition, WO3 layer covered on the surface of CuOx thin film can improve the stability of Cu2O in electrolytes.
关键词： p-n heterojunction,Tungsten oxide,Photoelectrochemical,Copper oxide,Magnetron reactive sputtering
更新于2025-09-23 15:22:29
-
Tungsten Oxide Based Sensor for Oxygen Detection
摘要： In this paper we report on the development tungsten oxide based chemiresistive sensors for the monitoring of oxygen at low temperatures (T ≤ 400 °C) in dry and humid air. The sensors were deposited onto alumina substrate by a combination of spin coating and a photolithographic process to define the sensing area. Our results show that the sensors comply with a linear relationship over a 0 to 20% concentration range, with a high response towards oxygen. The highest response was observed at 350 °C (ΔR/Ra = 7.8) in humid and in dry air (ΔR/Ra = 18). This result is a significant improvement over our previous experiments and we believe to take the concept of a metal-oxide based oxygen sensor a step closer.
关键词： metal oxide,tungsten oxide,oxygen detection,humidity effect
更新于2025-09-23 15:22:29
-
Synthesis of Tungsten Oxide Nanowires onto ITO Glass Using T-CVD
摘要： Tungsten oxide is an n-type semiconductor with interesting physical and chemical properties that make it suitable for various technological applications. Tungsten oxide nanowires were synthesized not only at low temperature but also without the use of any catalysts. The tungsten oxide nanowires were synthesized at 550 °C with tungsten layers onto the ITO glass using thermal chemical vapor deposition (T-CVD). The SEM image shows that the tungsten oxide nanowires are effectively grown with the 200 nm tungsten film. The Raman spectra shoulder at ~690 cm-1 proves the synthesized of tungsten oxide nanowires.
关键词： ITO glass,thermal chemical vapor deposition,Tungsten oxide nanowires
更新于2025-09-23 15:22:29
-
Aerosol assisted chemical vapor deposition (AACVD) synthesis of nanostructured cauliflower patterning in MWCNT doped tungsten oxide
摘要： We report nanostructured tungsten oxide (WO) cauliflowers for the first time that are fabricated onto silica glass substrate at 400 °C by aerosol assisted chemical vapor deposition using tungsten hexacarbonyl and multiwalled CNTs in toluene. The deposited films are characterized by Scanning electron microscopy, Energy dispersive x-ray spectroscopy, X-ray diffractometry, Fourier transform infrared and UV–VIS spectroscopy and four-point probe for microstructural, optical and electrical properties. Surface morphology exhibits the growth of nanocauliflowers followed by the aggregation of spherical nanoparticles with high angle grain boundaries. Structural information reveals the transformation of triclinic to tetragonal phase with preferential switching from (0 2 0) to (0 0 1) plane having signatures of W-O-W symmetric vibration between 700cm-1 and 900 cm-1, somewhat perturbed by the addition of doping. In additions, films show inconsistent variation in electrical resistivity (15–109) Ω-cm due to agglomeration of MWCNTs at grain boundaries and appearance of 'nanocracks' due to ionic radii mismatch of tungsten and CNTs at higher doping ratios. Black color films present decrease in optical transmittance for range of 300–400 nm attributed to trapping sites and defects generated due to incorporation of multiwalled CNTs. The splitting of Fermi level as a result of incorporation of MWCNTs caused the increase of band gap energy in range of 3.18 eV, useful in tungsten oxide based new material system which can act as the light harvesting material and energy storage simultaneously.
关键词： Thin film,Tungsten oxide,Nanocauliflowers,AACVD
更新于2025-09-23 15:22:29