KEY ENGINEERING MATERIALS
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2016
·
IF 0
Jian Wu,Cheng Zhang,Jin Feng Xia,Dan Yu Jiang
In this study, Yttria-stabilized zirconia (YSZ) electrochemical sensors attached with the WS2 sensing electrode (SE) were fabricated and examined for NO2 sensing properties. Due to its internal stratiform structure, surface and edge of the lamella have high chemical activity, WS2 was used as a kind of highly efficient catalyst. WS2 was partial oxidated to WO3 at 400°C, and with the increment of temperature, oxidation will accelerate. The ΔEMF to 500 ppm NO2 was as high as 125mv at 400°C, while the value of WO3-based sensor was as small as 10 mv in the same condition. These WS2-attached devices gave a linear correlation between EMF and the logarithm of NO2 concentration from 30 to 500 ppm in the temperature range 350–500°C. The response time of the device is about 1 min at 400°C.
研究领域:
材料科学
·
环境科学
✓ 已验证
DOI
Materials Today Communications
·
2024
·
IF 3.7
Yuhui Chen,Zhenhua Hao,Rulong Ma,Pei Wang,Yongchun Shu,Jilin He
In this study, a new unmixed carbon reduction method was proposed for the preparation of pure W powder. The effects of reduction temperature, reduction time, carbon distance and thickness of WO 3 layer on the phase of the reduction products were investigated. Results show that pure tungsten powder with a carbon content of less than 150 ppm can be prepared at 950 °C with a WO 3 layer thickness of 5 mm and a carbon distance of 2 mm. Increased carbon distance and thickness of WO 3 layer will lead to a decrease in the reduction ratio. Additionally, particle size of the tungsten powder gradually increases from 1 μm to 8 μm due to sintering with the extended reduction time. Furthermore, a two-stage carbon reduction process with WO 2 as an intermediate product is proposed, which avoids the sintering and growth of tungsten powder particles and the particle size of tungsten powder was successfully reduced to 2 μm. This unmixed carbon reduction reduces the carbon concentration and prevents the carbonization of tungsten powder. The experiment verifies the feasibility of carbon as a reducing agent in producing pure tungsten powder by reducing WO 3 .
研究领域:
材料科学
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冶金学
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2016
·Vol. 6
·期 10
·8061-8069
·
IF 3.289
Jingwen Qian,Zengying Zhao,Zhenguang Shen,Guoliang Zhang,Zhijian Peng,Xiuli Fu
W19O55 nano-/micron-rods (NMRs) were synthesized through calcining WO3 powders under a reducing atmosphere with S vapor in a vacuum furnace. For comparison, the as-prepared W19O55 NMRs were then annealed at 500 °C for 2 h to obtain WO3 NMRs. The decolourization of organic dyes methylene blue and rhodamine B under visible light by the two kinds of NMRs reveals that the oxygen-deficient W19O55 sample will present better comprehensive performance due to its stronger surface adsorption to the dye molecules, which could be attributed to the oxygen vacancies.
研究领域:
材料科学
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环境科学
✓ 已验证
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
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2018
·
IF 11.698
Yating Wang,Jinmeng Cai,Moqing Wu,Jiahuan Chen,Wanyue Zhao,Ye Tian,Tong Ding,Jing Zhang,Zheng Jiang,Xingang Li
Defect engineering is a promising strategy to enhance light absorption and charge separation of photocatalysts. Herein, we simply tailor the quantity and distribution of oxygen vacancies, as one of typical defects, on surface or bulk of thermal-treated WO 3 in the different H 2 concentration. The quantity of bulk oxygen vacancies on WO 3 consistently rises with the increased H 2 concentration, while that of surface oxygen vacancies presents a volcano-type variation. The sample of WO 3 -H20, thermal-pretreated in 20% H 2 , contains the largest amount of surface oxygen vacancies. Our results show that both surface and bulk oxygen vacancies on WO 3 can promote the visible light photocatalytic activity in water splitting, however, in different ways. Bulk oxygen vacancies mainly promote the visible light harvesting and slightly restrain the electrons and holes recombination by narrowing band gap energy ( E g ), while surface oxygen vacancies significantly increase the charge-carriers separation efficiency by lowering valence band edge (VBE). Compared with the light absorption, the separation of electrons and holes is more critical in photocatalytic oxygen evolution over WO 3 , revealing the more decisive role of surface oxygen vacancies than bulk oxygen vacancies. Expectedly, WO 3 -H20 shows the highest charge-carriers separation efficiency and visible light photocatalytic performance. Our work provides a new insight into designing of efficient defect-engineered semiconductors for the related solar light utilization processes.
研究领域:
材料科学
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能源科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2019
·
IF 4.175
Yunfang Huang,Hui Xu,Dan Luo,Yuezhu Zhao,Yu Fang,Qiyao Guo,Yuelin Wei,Leqing Fan,Jihuai Wu
To improve the utilization efficiency of solar energy and separation of photogenerated carries, a novel three-dimensional (3D) WO 3-x /Bi/BiOCl hierarchical heterostructures with broad spectrum responsive photocatalytic activity have been fabricated through a facile solvothermal technique. The influences of varying loading of WO 3-x on the physical performances of the as-obtained composites were systematically characterized by X-ray diffraction, scanning electron microscope, transmission electron microscopy , X-ray photoelectron spectroscopy, optical absorbance, photoluminescence and specific surface areas. The WO 3-x /Bi/BiOCl displayed a strong optical absorption from 250 to 2500 nm, and showed the superior photocatalytic performance in degradation of rhodamine B (RhB) than that of individual components. Among the as-prepared samples, the sample S24 with the appropriate content of WO 3-x displayed the best photocatalytic performance, which can photodegrade RhB with the efficiency of 100%, 100% and 96% under the UV light within 8 min, visible light within 3 min and near-infrared light within 120 min exposure, respectively. Furthermore, a plausible mechanism of the RhB degradation on WO 3-x /Bi/BiOCl photocatalysts under the near-infrared light irradiation was proposed according to the photocatalytic activity and radical species trapping experiments.
研究领域:
材料科学
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环境科学
✓ 已验证
DOI
高影响因子
Bioresource Technology Reports
·
2018
·
IF 0
Ning Shi,Qiying Liu,Xiong He,Hu Cen,Rongmei Ju,Yulan Zhang,Longlong Ma
Solid Al 2 (WO 4 ) 3 was prepared by coprecipitation and employed to catalyze the conversion of cellulose into lactic acid. Under optimum condition of 220 °C and 3 h, 46% of lactic acid could be produced from cellulose with the aid of Al 2 (WO 4 ) 3 . The catalytic activity of the catalyst is ascribed to the synergistic effect of the W O species and the adjacent Al OH species in Al 2 (WO 4 ) 3 . The formation of hydrogen bond and coordination bond between the W O species and the hydroxyl group in the carbohydrates plays critical role in the catalytic conversion of cellulose into lactic acid. The catalyst has good hydrothermal stability and can be easily to be recycled.
研究领域:
催化化学
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生物质转化
·
绿色化学
✓ 已验证
DOI
INTERNATIONAL JOURNAL OF REFRACTORY METALS & HARD MATERIALS
·
2018
·
IF 2.606
Yijie Wu,Jie Dang,Zepeng Lv,Run Zhang
In the present study, a new and simple method to prepare tungsten and tungsten carbides powders was proposed by using WO 3 powders as the raw material and CH 3 OH vapor as the reduction and carbonization agent. Both thermodynamic and experimental studies were carried out, and based on the results, the reaction routes were obtained. It was found that at low and moderate temperatures, the final product of WC was formed via intermediates of W 18 O 49 , WO 2 , partial metallic W and W 2 C; while at high temperature, WO 3 was first reduced to WO 2 with the intermediate phase of W 18 O 49 , and then reduced to W. The morphology of final products almost retained the same shape as that of raw materials WO 3 at low temperature, however, the large particles with blocky shape disappeared and the products were all small W particles with polyhedral shape at high temperature. Furthermore, the reaction mechanisms were proposed: the pseudomorphic transformation mechanism dominated the reaction at low temperature, but at high temperature, the reduction obeyed the chemical vapor transport mechanism, which is beneficial for grain refining of final product.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2020
·
IF 8.758
Fang Peng,Weiwei Yu,Yue Lu,Yan Sun,Xiuli Fu,Jia ming Hao,Xin Chen,Rui Cong,Ning Dai
To verify the effect of oxygen vacancy on gas sensitivity, we have systematically investigated the gas-sensing performance of copper oxide/substoichiometric tungsten oxide (CuO/WO3–x) nanocomposite sensors. Oxygen deficiency in WO3–x facilitates the reaction of hydrogen sulfide (H2S) gas with chemisorbed oxygen species (i.e., O2–, O–, and O2–) at low temperature. The oxygen/sulphur exchange reaction between CuO and H2S in the sensing process can achieve room temperature operation of gas sensors. After the WO3–x nanorods were modified by a low content of CuO nanoparticles (Cu:W = 1:20), the sensors present an n-type sensing behavior. Their best working temperatures drop from 289 °C (or 386 °C) to 99 °C (or 70 °C) at which the responses are improved by 14 to 163 times for different x values. Among them, CuO(L)/W5O14 shows the highest sensitivity of 1575.7 to 10 ppm H2S at 99 °C and 171.5 to 10 ppm H2S at room temperature. Once WO3–x were loaded with a high concentration of CuO nanoparticles (Cu:W = 1:2), they exhibit a p-type behavior, and the optimal working temperatures reduce suddenly to room temperature at which CuO(H)/W18O49 displays the most sensitive response of 7.2 even toward trace amounts of H2S as low as 100 ppb. In addition, p-type CuO weakens the metal-like characteristics of W18O49 and such weakening effect enhances with an increase in the CuO content. Therefore, the sensing performance of the CuO/W18O49 composite is the best among the four CuO/WO3–x sensors. The two designs for low and high Cu/W molar ratios all achieve enhanced room-temperature H2S gas response, with a fast recovery time of ∼60 s under heating pulse, as well as an excellent selectivity, which makes the sensors a promising candidate for practical applications. Moreover, the micro-Raman spectra confirmed CuS formation and the thermal effect on the decomposition of CuS in the sensing process was studied.
研究领域:
材料科学
·
传感器技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MOLECULES
·
2024
·Vol. 29
·期 13
·3126
·
IF 4.2
Dong Li,Siyu Tian,Qiuhua Qian,Caiyun Gao,Hongfang Shen,Fei Han
Cesium doped WO3(Cs-WO3) photocatalyst with high and stable oxidation activity was successfully synthesized by a one-step hydrothermal method using Cs2CO3as the doped metal ion source and tungstic acid (H2WO4) as the tungsten source. A series of analytical characterization tools and oxygen precipitation activity tests were used to compare the effects of different additions of Cs2CO3on the crystal structure and microscopic morphologies. The UV–visible diffuse reflectance spectra (DRS) of Cs-doped material exhibited a significant red shift in the absorption edge with new shoulders appearing at 440–520 nm. The formation of an oxygen vacancy was confirmed in Cs-WO3by the EPR signal, which can effectively regulate the electronic structure of the catalyst surface and contribute to improving the activity of the oxygen evolution reaction (OER). The photocatalytic OER results showed that the Cs-WO3-0.1 exhibited the optimal oxygen precipitation activity, reaching 58.28 µmol at 6 h, which was greater than six times higher than that of WO3-0 (9.76 μmol). It can be attributed to the synergistic effect of the increase in the conduction band position of Cs-WO3-0.1 (0.11 V) and oxygen vacancies compared to WO3-0, which accelerate the electron conduction rate and slow down the rapid compounding of photogenerated electrons–holes, improving the water-catalytic oxygen precipitation activity of WO3.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2025
·
IF 11.3
Chaolong Liu,Keng Xuan,Yaoping Guo,Hao Jiang,Wenjie Ma,Xuegang Wang,Zhongkui Zhou,Jun Li,Yadan Guo
WO 3 -based materials are theoretically promising photocatalysts for uranium(VI) removal due to their stability and narrow bandgap (∼2.8 eV), but they are limited by a lack of adsorption sites and a tendency for photogenerated electron-hole pairs to recombine. Herein, La-doped WO 3 (W 0.9 La 0.1 O 3-x ) rich in oxygen vacancies (OVs) was prepared via a facile hydrothermal method. La doping and the introduction of OVs provided abundant active sites, optimized the band structure, increased electron density, and inhibited electron-hole pair recombination of W 0.9 La 0.1 O 3-x , which resulted in a maximum U(VI) extraction capacity of up to 1199.73 mg/g through synergistic adsorption-photocatalytic reduction processes. Interestingly, W 0.9 La 0.1 O 3-x demonstrated excellent stability and increased recyclability, superior to that of most reported adsorbents and photocatalysts, probably owing to the strong stability of W and La atoms as well as the additional OVs formed from self-reduction of W 0.9 La 0.1 O 3-x during photocatalytic reaction process. Overall, this study expands the application of WO 3 -based materials for U(VI) removal from wastewater and provides valuable theoretical insights and technical guidance for addressing the challenge of balancing removal rate and stability of U(VI) extraction materials.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2020
·Vol. 55
·期 26
·11829-11840
·
IF 3.553
Xie Wenwen,Huang Zeai,Wang Ruiqi,Wen Cheng,Zhou Ying
Photocatalytic production of green oxidation reagents as an economical and environmental-friendly process is a promising strategy to replace the traditional production processes. In the present study, a series of 1.0 wt% Pt/WO 3 photocatalysts with different surface chemical states of Pt were successfully fabricated. The different surface metallic Pt (Pt 0 ) and oxidized Pt (PtO x ) ratios on WO 3 showed significant effects on the photocatalytic activities for strong oxidants of peroxydisulfate ( \( {\text{S}}_{ 2} {\text{O}}_{8}^{2 - } \) ) and hydrogen peroxide (H 2 O 2 ) formations. It is proposed that surface Pt 0 and PtO x functioned as reduction site for O 2 reduction to H 2 O and oxidation site for H 2 O oxidation to H 2 O 2 , respectively, during the photocatalytic process. As a result, a higher surface composition of Pt 0 prepared using photodeposition (PD) method led to the formation of higher amount of \( {\text{S}}_{ 2} {\text{O}}_{8}^{2 - } \) . On the other hand, PtO x -loaded WO 3 using impregnation (IM) method showed significant formations of \( {\text{S}}_{ 2} {\text{O}}_{8}^{2 - } \) and H 2 O 2 simultaneously. This work provided a new idea for the design of noble metal Pt-supported WO 3 for efficiently photocatalytic generation of \( {\text{S}}_{ 2} {\text{O}}_{8}^{2 - } \) and H 2 O 2 .
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2021
·Vol. 32
·期 11
·15242-15250
·
IF 2.478
Guo Xiaogang,Liang Taotao,Bao Hebin,Yuan Chengsong,Lai Chuan,Tang Chuyue,Giwa A. S.
The fabrication of functional nanocomposite films by electrically driven techniques is an emerging method that has attracted increasing research interest because of advantages such as easy operation, low-cost, no secondary pollution. In this study, electrophoretic assembly technique (EAT) was firstly developed to design the promising novel nano-aluminum@tungsten trioxide (nano-Al@WO 3 ) energetic coating with even distribution of nanoparticles under room temperature and pressure conditions, using the mixed liquor of isopropyl alcohol, PEG-1000, and polyethyleneimine as the optimal dispersion liquid for EAT. High crystallinity and purity of product was demonstrated by X-ray diffractometer. Differential scanning calorimetry (DSC) results that the obtained Al@WO 3 was an outstanding high-energy coating with a high output of heat (~ 2400 J/g) due to the sufficient thermite reaction between nano-Al and WO 3 particles, and the heat-release process of product can be highly controlled by adjusting the solid loading concentration ratio of nano-Al@WO 3 before EAT. Thus, the fabrication method of EAT proposed here has great potentials to high-efficient construction or design of various energetic nanocomposite coatings such as thermite and bimetallic reactive composites with wide applications.
研究领域:
材料科学
·
能量材料
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）