JOURNAL OF SOLID STATE ELECTROCHEMISTRY
·
2016
·Vol. 21
·期 2
·469-476
·
IF 2.327
Li Min,Gao Bingliang,Liu Chengyuan,Chen Wenting,Wang Zhaowen,Shi Zhongning,Hu Xianwei
AlCl 3 /amide (acetamide, propionamide, butyramide) ionic liquids were used as the electrolytes to study the electrodeposition behavior of aluminum on a tungsten electrode. Cyclic voltammograms on the tungsten electrode indicate that Al(III) ions can be reduced to aluminum only within the molar ratio range of 1.1 to 1.5 and the reduction potentials of Al(III) ions strongly depend on the molar ratio of AlCl 3 /amide. Raman spectra results reveal that the electroactive specie of AlCl 3 /amide ionic liquids is Al 2 Cl 7
− . Aluminum coatings were prepared at −0.25 V (vs. Al/Al 3+ ) and at 313 K in AlCl 3 /amide ionic liquids with the molar ratio of 1.3. The SEM and cross-sectional SEM images show that all the obtained aluminum films are silver-colored, thick, and adherent. The EDS and XRD analysis confirm that the obtained deposits are pure aluminum. The present results can provide a new route for aluminum electrodeposition under ambient conditions.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
Advanced Photonics Nexus
·
2023
·
IF 0
Haiyang Liu,Zongnan Zhang,Yingqiu Li,Yaping Wu,Zhiming Wu,Xu Li,Chunmiao Zhang,Feiya Xu,Junyong Kang
Achieving valley pseudospin with large polarization is crucial in the implementation of quantum information applications. Transition metal dichalcogenides (TMDC) with different phase structures provide an ideal platform for valley modulation. The valley splitting has been achieved in hybrid phase WSe2, while its valley polarization remains unstudied. Magnetic field controllable valley polarization is explored in WSe2 with coexistence of H and T phases by an all-optical route. A record high valley polarization of 58.3% is acquired with a 19.9% T phase concentration under a 4-T magnetic field and nonresonant excitation. The enhanced valley polarization is dependent on the phase component and shows various increasing slopes, owing to the synergy between the T phase WSe2 and the magnetic field. The magnetic field controlled local magnetic momentums are revealed as the mechanism for the large valley polarization in H / T-WSe2. This speculation is also verified by theoretical simulations of the nonequilibrium spin density. These results display a considerable valley magnetic response in phase-engineered TMDC and provide a large-scale scheme for valley polarization applications.
研究领域:
凝聚态物理
·
材料科学
·
量子信息
·
光学调控
·
二维材料
✓ 已验证
DOI
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
·
生物质转化
·
绿色化学
✓ 已验证
DOI
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
·
环境科学
✓ 已验证
DOI
高影响因子
ADVANCED ENGINEERING MATERIALS
·
2022
·Vol. 25
·期 5
·2200175
·
IF 4.122
Meiqin Zeng,Youtao Pan,Weifeng Liu,Jie Cui,Zhongchen Lu,Min Zhu
This work prepares nanocrystalline tungsten carbide (WC) powder using conventional ball milling or plasma milling (P-milling) to process tungsten trioxide (WO 3 )–carbon (C) mixtures, with subsequent carbothermal reduction. The aim is to assess the effects of a discharge plasma on the microstructure of these materials. The results indicates that WC powders with particle sizes of less than 100 nm could be fabricated through heating at a relatively low temperature of 1150 °C for 1 h under vacuum after P-milling. This process is found to allow a lower processing temperature and provided more complete carburization in comparison with conventional ball milling. P-milling is determined to produce more loosely adhering WO 3 nanoparticles and a higher surface area, resulting in more reactive sites and a larger contact area between WO 3 nanoparticles and C atoms. This technique simultaneously generates more oxygen vacancies and defects on the surfaces of the WO 3 and C, respectively, based on the use of a plasma discharge. It is evident that this new technology permits nanocrystalline WC to be readily obtained from WO 3 and C in a reduced time span and at a lower cost and greater efficiency. This technique could also be used to fabricate WC nanopowders on an industrial scale.
研究领域:
材料科学
·
纳米技术
✓ 已验证
DOI
高影响因子
Frontiers of Chemical Science and Engineering
·
2013
·Vol. 7
·期 4
·422-427
·
IF 0
Liu Liyan,Zhang Yu,Tan Wei
Phosphotungstic acid/activated carbon (PTA/AC) catalysts with various AC sizes or PTA content have been synthesized and characterized by N 2 physisorption, X-ray diffraction, Fourier transform infrared spectroscopy and temperature programmed desorption of ammonia. These catalysts were then evaluated in terms of the removal of dibenzothiophene (DBT) by ultrasoundassisted oxidative desulfurization process. The results showed that the DBT conversion obviously increased with the decrease of AC support size and the increase of PTA content. After supporting PTA on AC, the DBT conversion can be improved by 38.9% after ultrasound irradiation for 10 min. In addition, the stability tests of PTA/AC showed that the catalytic oxidative activity of PTA/AC was nearly kept constant after ultrasound irradiation for 20 min, which makes it a promising catalyst to use in ultrasound-assisted oxidative desulfurization process.
研究领域:
催化化学
·
环境科学
✓ 已验证
DOI
ACS Sustainable Chemistry & Engineering
·
2023
·
IF 8.4
Man Yang,Yuxiang Jiao,Jianglin Duan,Keying Wu,Hailiang Song,Shaodong Sun,Yujing Ren
Taking the background of the ambiguous role of oxophilic metal oxide in metal-acid bifunctional catalysts for the important field of tetrahydrofurfuryl alcohol (THFA) hydrogenolysis, a linear relationship between the W═O/W–OH content in sub-nano-Rh-supported WOx and 1,5-pentanediol (1,5-PeD) yields from THFA hydrogenolysis has been established. It reveals that the higher reduction temperature promotes the surface Rh/W ratio. Thus, hydrogen spillover is facilitated, leading to more surface W═O structures and thereby more in-situ-reduced W–OH generation. W–OH structures work as the active sites to provide in situ Brønsted acid, resulting in enhanced selective activation for secondary C–O bonds of THFA. This discovery reveals the unique role of the surface structure on oxophilic metal oxide in chemoselective hydrogenolysis of the secondary C–O bond in polyols.
研究领域:
催化化学
·
材料科学
✓ 已验证
DOI
高影响因子
CATALYSIS LETTERS
·
2021
·Vol. 151
·期 8
·2250-2256
·
IF 3.186
Liu Qi,Wang Shihao,Xu Gang,Wu Minghong,Chen Jianjun,Li Junhua
Abstract A novel TiO 2 -supported vanadium-substituted tungstophosphoric acid (PW 11 V/TiO 2 ) catalyst was designed and applied for selective catalytic reduction of NO x by NH 3 . Compared with the commercial tungstophosphoric acid (PW 12 /TiO 2 ), PW 11 V/TiO 2 displayed a nearly 90% activity improvement at 300 °C. In addition, the favorable resistance and stability to SO 2 were also obtained over PW 11 V/TiO 2 catalyst. Phase analysis and spectroscopy results indicated the vanadium was successfully incorporated into the molecular structure of PW 12 , and the Keggin framework still keep stable over the TiO 2 support. H 2 -TPR test proved the incorporation of vanadium promoted the redox ability of PW 11 V. The present study provides us an effective way to improve the performance of catalytic removal of NO x through tungstophosphoric acid catalyst. Graphic Abstract
After introduction of V species, the obtained PW 11 V/TiO 2 catalyst show better NH 3 -SCR performance and N 2 selectivity than PW 12 /TiO 2 catalyst.
研究领域:
环境科学
·
催化化学
✓ 已验证
DOI
高影响因子
Frontiers in Chemistry
·
2020
·
IF 3.693
Xi Senliang,Wang Xiaojun,Wu Dan,Hu Xingtao,Zhou Shixue,Yu Hao
Phosphotungstic acid (HPW) as a polyoxometalate was selected as the active component of the catalyst. The activated carbon supported different percentage of HPW catalysts were prepared by impregnation and were characterized by X-ray diffraction (XRD), nitrogen adsorption, Fourier transform infrared (FTIR), and scanning electron microscope (SEM). The results showed that the HPW retained the original Keggin structure after being supported on activated carbon, the specific surface of the HPW/C was much bigger than that of pure HPW. The catalytic performance of HPW/C in the hydrogen generation reaction by hydrolysis of sodium borohydride in seawater and in deionized water were studied. 2.5 wt.% HPW/C showed the fastest hydrolysis reaction rate and the biggest volume of hydrogen generated. As for hydrolysis of sodium borohydride, catalytic effect of HPW/C was better in seawater than in distilled water. HPW dispersed on activated carbon is a real promising catalytic system for the development of hydrogen generation by hydrolysis of NaBH4 in seawater.
研究领域:
化学
·
材料科学
·
能源科学
✓ 已验证
DOI
PubMed
高影响因子
APPLIED CATALYSIS A-GENERAL
·
2021
·
IF 5.706
Hui Chen,Jie He,Jinsheng Sun
The production of cyclohexanone, of industrial importance, is at a distance to environment friendly and efficiency. As a solution, a mild sustainable catalytic hydrogenation is presented herein, of phenol into cyclohexanone on Pd/C with potassium formate the hydrogen donor under open atmosphere. Some important reaction conditions, such as temperature, reaction time, catalyst, amount of potassium formate, etc. were investigated and analyzed. The positive growth was found to accelerate the conversion rate of phenol while reducing cyclohexanone selectivity by weakening the protection of phosphotungstic acid. Phosphotungstic acid was confirmed to be the co-catalyst exhibiting the highest activity under given conditions. Based on experiments, we have made reasonable assumptions about the reaction mechanism, while the reaction kinetics proves high reaction rates within a wide temperature range, indicating the reaction to be quick process. Furthermore, the good reusability and recyclability of Pd/C catalyst is verified to benefit future industrial applications.
研究领域:
化学工程
·
催化化学
✓ 已验证
DOI
高影响因子
Processes
·
2021
·Vol. 9
·期 11
·1923
·
IF 2.847
Bo Wang,Qiaowen Yang
Every year, large amounts of selective catalytic reduction (SCR) catalysts with losing catalytic activity and failing to be regenerated need to be regenerated, which will result in acute pollution. Recycling valuable metals from spent SCR catalysts can not only solve environmental problems, but also save resources. The process of sodium roasting and water leaching is able to effectively extract vanadium (V) and tungsten (W) from spent SCR catalysts. To improve the efficiencies of V and W, different sodium additives were first investigated in the roasting process. The results revealed that the process of NaCl-NaOH composite roasting and water leaching showed superior leaching efficiencies of V and W, which can reach 91.39% and 98.26%, respectively, and simultaneously, it can be found that adding low melting point NaOH promoted mass transfer as compared with the melting points of different sodium additives. Next, a single-factor experiment was conducted to investigate different roasting conditions, such as roasting temperature, roasting time, mass ratio of sodium additive and catalyst, and mass ratio of NaCl and NaOH, on the leaching efficiencies of V and W. Then, a three-level and four-factor orthogonal experiment and a weight matrix analysis were used to optimize the roasting parameters. The results showed that roasting temperature had the most significant effect on the leaching efficiencies of V and W, and the optimal roasting conditions were as follows: the roasting temperature was 750 °C, the roasting time was 2.5 h, the mass ratio of sodium additive and catalyst was 2.5, and the mass ratio of NaCl and NaOH was 1.5. Under the optimal roasting conditions, the leaching efficiencies of V and W were 93.25% and 99.17%, respectively. The results of XRD analysis inferred that VO2coming from the decomposition of VOSO4in spent SCR catalysts may first oxidize into V2O5and then react with sodium additives to produce NaVO3. The formation of titanium-vanadium oxide ((Ti0.5V0.5)2O3) was a part reason of hindering the leaching of vanadium. With the increase of roasting temperature, TiO2converted into Na2Ti3O7, which indicated that the main structure of the catalyst was destroyed, and simultaneously, more characteristic peaks of sodium metavanadate and sodium tungstate appeared, thus enhancing the leaching of V and W. Finally, it can be seen that the process of NaCl-NaOH roasting and water leaching remained higher leaching efficiencies of V and W and lower roasting temperature by comparing with leaching efficiencies of V and W in different processes of recycling SCR catalyst. The process of NaCl-NaOH composite roasting and water leaching provided a strategy with a highly efficient and clean route to leach V and W from spent SCR catalyst. The orthogonal experiment and weight matrix analysis in our study can be used as a reference to optimize the reaction conditions of a multiple indexes experiment.
研究领域:
环境科学
·
冶金工程
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Mengen Hu,Xincan Gao,Zhen Wang,Xian Dang,Chengwan Yang,Xinyang Li,Ming Li,Yue Li,Xiaoye Hu,Zhulin Huang
Tungsten carbide (WC) cemented carbide plays a crucial role in cutting and mechanical processing. However, the grain coarsening that inevitably occurs during the high temperature sintering process of WC leads to a reduction in mechanical properties. This study presents a strategy for the one-step synthesis of tantalum carbide (TaC) grain inhibitors to enhance ultrafine grain WC ceramics. Specifically, WC-xTaC (where x = 0 wt%, 1 wt%, 2 wt%, 3 wt%, and 4 wt%) powders were synthesized directly in one step using a liquid phase method, thereby eliminating the effects of the ball milling process on the defect density and surface energy of the powders. The mechanical properties of the sintered blocks were evaluated after the synthesized WC-xTaC powders underwent hot press sintering. The results demonstrate a reduction in the grain size of WC from 1.96 μm to 850 nm after sintering compared to WC ceramics without TaC doping. The density of the material improved from 91.4 % to 97.8 %, while the hardness increased from 16.3 GPa to 24 GPa, reflecting an overall enhancement of 47.2 %. This research provides an optimized approach for the fabrication of ultrafine grained WC ceramics.
研究领域:
材料科学
·
陶瓷工程
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）