用混合煅烧法制备了CuWO_4/C复合物,并采用XRD、SEM、和BET等技术对其结构进行表征。以CuWO_4/C复合物为催化剂、过氧化氢为氧化剂、1-乙基-3-甲基咪唑硫酸乙酯盐离子液体为萃取剂氧化脱除模拟油中的二苯并噻吩(DBT)。考察了反应温度、...用混合煅烧法制备了CuWO_4/C复合物,并采用XRD、SEM、和BET等技术对其结构进行表征。以CuWO_4/C复合物为催化剂、过氧化氢为氧化剂、1-乙基-3-甲基咪唑硫酸乙酯盐离子液体为萃取剂氧化脱除模拟油中的二苯并噻吩(DBT)。考察了反应温度、双氧水加入量、萃取剂加入量等因素对脱硫效果的影响。结果表明,在相同的实验条件下,相比于CuWO_4,CuWO_4/C复合物具有更高的脱硫率。在模拟油为5.0 m L、催化剂加入量为0.02 g、H_2O_2加入量0.2 m L、萃取剂加入量1.0 m L、反应温度70℃、反应时间180 min的最佳实验条件下,DBT转化率可达到98.2%,催化剂循环使用四次活性没有明显降低。展开更多
WO3 photocatalyst decorated with highly dispersed CoWO4 or CuWO4 nanoparticles(CoWO4/WO3 or CuWO4/WO3) was successfully synthesized using an in-situ impregnation method followed by solid-state reaction. The structure,...WO3 photocatalyst decorated with highly dispersed CoWO4 or CuWO4 nanoparticles(CoWO4/WO3 or CuWO4/WO3) was successfully synthesized using an in-situ impregnation method followed by solid-state reaction. The structure, morphology, photophysical property, and photocatalytic degradation mechanism of the CoWO4/WO3 or CuWO4/WO3 samples were investigated by XRD, SEM, TEM, EDS, HR-TEM, UV-vis DRS, SPV, and active trapping techniques. The XRD, SEM, and TEM results have revealed that CoWO4 or CuWO4 are highly dispersed on the WO3 surface, when the loading amount of CoWO4 or CuWO4 is small. However, obvious agglomeration is observed for the CoWO4 or CuWO4 particles, when the loading amount of CoWO4 or CuWO4 was increased. The visible-light photocatalytic degradation of RhB shows that all CoWO4/WO3 or CuWO4/WO3 samples exhibit superior photocatalytic performance as compared to pure WO3. This is mainly attributed to the formation of type II heterojunction between WO3 and CoWO4 or CuWO4, which can promote the photogenerated electrons and holes separation and transfer. Moreover, it is found that 0.2% CoWO4/WO3 or 0.2% CuWO4/WO3, in which MWO4 nanoparticles are uniformly dispersed on the surface of WO3, can achieve the most excellent photocatalytic activity among CoWO4/WO3 or CuWO4/WO3 samples, respectively. As compared with WO3, an enhancement about 9.1 times or 6.8 times in photocatalytic activity is observed on 0.2% CoWO4/WO3 or 0.2% CuWO4/WO3, respectively. Furthermore, the active species trapping experiment demonstrates that ·OH, h+, and ·O-2 generated during the photocatalytic process are all the reactive species in photocatalytic degradation of Rhodamine B(RhB) on CoWO4/WO3 or CuWO4/WO3. This study presents a strategy to design superior photocatalyst for organic compound degradation.展开更多
Iron(Fe)was successfully doped in CuWO4 photoanode films with a combined liquid-phase spin-coating method via the dopant sources of Fe(NO3)3,FeSO4 and FeCl3.The microstructure of the prepared films was characterized b...Iron(Fe)was successfully doped in CuWO4 photoanode films with a combined liquid-phase spin-coating method via the dopant sources of Fe(NO3)3,FeSO4 and FeCl3.The microstructure of the prepared films was characterized by x-ray diffraction,scanning electron microscopy,and atomic force microscopy.The light absorption and photoelectric conversion properties were evaluated by the UV-visible absorption spectra and monochromatic incident photon-to-electron conversion efficiency.The chemical composition and element combination of the samples were examined by x-ray photoelectron spectroscopy.A linear sweep voltammetric and stability test(I-t)were performed with an electrochemical workstation.The results show that the samples are uniform with a thickness of approximately 800 nm and that the photoelectrochemical performance of the doped films is heavily dependent on the Fe source and dopant concentration.Upon optimizing the doping conditions of Fe(NO3)3 and the optimal source,the photocurrent density in the Fe-doped CuWO4 photoanode film is improved by 78%from 0.267 mA/cm2 to 0.476 mA/cm2 at 1.23 V vs reversible hydrogen electrode.The underlying causes are discussed.展开更多
CuWO4,as an n-type oxide semiconductor with a bandgap of 2.2 eV,has stimulated enormous interest as a potential broad-spectrum-active photocatalyst for environmental pollution remediations.However,rapid charge recombi...CuWO4,as an n-type oxide semiconductor with a bandgap of 2.2 eV,has stimulated enormous interest as a potential broad-spectrum-active photocatalyst for environmental pollution remediations.However,rapid charge recombination greatly hinders its practical applications.Herein,we present a cascaded electron transition pathway in a ternary heterostructure consisting of CdS quantum dots,carbon dots(CDs)and CuWO4 hollow spheres,which proves to greatly facilitate the photogenerated electron-hole separation,and eventually boosts the degradation efficiency of phenol and congo red by 100%and 46%compared to bare CuWO4.The enhanced performance of the CuWO4/CdS/CDs heterostructure mainly originates from the unidirectional electron migration from CdS to CuWO4 and then to the organics through CDs.This work elucidates the electron transfer kinetics in multi-phase system and provides a new design paradigm for optimizing the properties of CuWO4 based photocatalysts.展开更多
CuW（1-x）MoxO4 solid solution of CuWO4 and CuMoO4, which is a copper-based multi-component oxide semiconductor, possesses much narrower band gap than CuWO4. In theory, it can absorb a larger part of the visible spect...CuW（1-x）MoxO4 solid solution of CuWO4 and CuMoO4, which is a copper-based multi-component oxide semiconductor, possesses much narrower band gap than CuWO4. In theory, it can absorb a larger part of the visible spectrum, widening the use of solar spectroscopy and obtaining a higher photo-to-chemical conversion efficiency. In this study, CuW（1-x）MoxO4 thin-film photoanodes on conducting glass were prepared using a simple and low-cost spray pyrolysis method. The resulting CuW（1-x）MoxO4 photoanodes perform higher photocurrent than CuWO4 photoanodes under AM 1.5 G simulated sunlight illumination（100 m W cm^（-2））in 0.1 mol L^（-1） phosphate buffer at pH 7. Combined with IPCE and Mott-Schottky analysis, the enhancement of the photocurrent is due to the improvement of photon utilization and the increase of carrier concentration with the incorporation of Mo atoms. Moreover, with the optimal Mo/W atomic ratio,the photocurrent density increases obviously from 0.07 to 0.46 m A cm^（-2） at 1.23 V（RHE） bias. In addition, compared with particle-assembled thin-film photoanodes prepared by solidphase reaction and drop-necking treatment, the photoanodes prepared by spray pyrolysis have obvious advantages in terms of reducing resistance and facilitating charge transport.展开更多
文摘用混合煅烧法制备了CuWO_4/C复合物,并采用XRD、SEM、和BET等技术对其结构进行表征。以CuWO_4/C复合物为催化剂、过氧化氢为氧化剂、1-乙基-3-甲基咪唑硫酸乙酯盐离子液体为萃取剂氧化脱除模拟油中的二苯并噻吩(DBT)。考察了反应温度、双氧水加入量、萃取剂加入量等因素对脱硫效果的影响。结果表明,在相同的实验条件下,相比于CuWO_4,CuWO_4/C复合物具有更高的脱硫率。在模拟油为5.0 m L、催化剂加入量为0.02 g、H_2O_2加入量0.2 m L、萃取剂加入量1.0 m L、反应温度70℃、反应时间180 min的最佳实验条件下,DBT转化率可达到98.2%,催化剂循环使用四次活性没有明显降低。
基金supported financially by the National Natural Science Foundation of China(21573101)the Program for Liaoning Excellent Talents in University(LR2017011)+1 种基金the support plan for Distinguished Professor of Liaoning Province([2015]153)the Liaoning BaiQianWan Talents program([2017]96)
文摘WO3 photocatalyst decorated with highly dispersed CoWO4 or CuWO4 nanoparticles(CoWO4/WO3 or CuWO4/WO3) was successfully synthesized using an in-situ impregnation method followed by solid-state reaction. The structure, morphology, photophysical property, and photocatalytic degradation mechanism of the CoWO4/WO3 or CuWO4/WO3 samples were investigated by XRD, SEM, TEM, EDS, HR-TEM, UV-vis DRS, SPV, and active trapping techniques. The XRD, SEM, and TEM results have revealed that CoWO4 or CuWO4 are highly dispersed on the WO3 surface, when the loading amount of CoWO4 or CuWO4 is small. However, obvious agglomeration is observed for the CoWO4 or CuWO4 particles, when the loading amount of CoWO4 or CuWO4 was increased. The visible-light photocatalytic degradation of RhB shows that all CoWO4/WO3 or CuWO4/WO3 samples exhibit superior photocatalytic performance as compared to pure WO3. This is mainly attributed to the formation of type II heterojunction between WO3 and CoWO4 or CuWO4, which can promote the photogenerated electrons and holes separation and transfer. Moreover, it is found that 0.2% CoWO4/WO3 or 0.2% CuWO4/WO3, in which MWO4 nanoparticles are uniformly dispersed on the surface of WO3, can achieve the most excellent photocatalytic activity among CoWO4/WO3 or CuWO4/WO3 samples, respectively. As compared with WO3, an enhancement about 9.1 times or 6.8 times in photocatalytic activity is observed on 0.2% CoWO4/WO3 or 0.2% CuWO4/WO3, respectively. Furthermore, the active species trapping experiment demonstrates that ·OH, h+, and ·O-2 generated during the photocatalytic process are all the reactive species in photocatalytic degradation of Rhodamine B(RhB) on CoWO4/WO3 or CuWO4/WO3. This study presents a strategy to design superior photocatalyst for organic compound degradation.
基金Project supported by the National Natural Science Foundation of China(Grant No.11204238)the Natural Science Foundation of Shaanxi Province,China(Grant No.2017JM1030).
文摘Iron(Fe)was successfully doped in CuWO4 photoanode films with a combined liquid-phase spin-coating method via the dopant sources of Fe(NO3)3,FeSO4 and FeCl3.The microstructure of the prepared films was characterized by x-ray diffraction,scanning electron microscopy,and atomic force microscopy.The light absorption and photoelectric conversion properties were evaluated by the UV-visible absorption spectra and monochromatic incident photon-to-electron conversion efficiency.The chemical composition and element combination of the samples were examined by x-ray photoelectron spectroscopy.A linear sweep voltammetric and stability test(I-t)were performed with an electrochemical workstation.The results show that the samples are uniform with a thickness of approximately 800 nm and that the photoelectrochemical performance of the doped films is heavily dependent on the Fe source and dopant concentration.Upon optimizing the doping conditions of Fe(NO3)3 and the optimal source,the photocurrent density in the Fe-doped CuWO4 photoanode film is improved by 78%from 0.267 mA/cm2 to 0.476 mA/cm2 at 1.23 V vs reversible hydrogen electrode.The underlying causes are discussed.
基金supported by the National Natural Science Foundation of China(No.21875048)Guangdong Natural ScienceFoundation(No.2017A030313255)+3 种基金Major Scientific Project of Guangdong University(No.2017KZDXM059)Yangcheng Scholars Research Project of Guangzhou(No.201831820)Science and Technology Research Project of Guangzhou(No.201804010047)Guangzhou University’s 2017 Training Program for Young TopNotch Personnel(No.BJ201704)。
文摘CuWO4,as an n-type oxide semiconductor with a bandgap of 2.2 eV,has stimulated enormous interest as a potential broad-spectrum-active photocatalyst for environmental pollution remediations.However,rapid charge recombination greatly hinders its practical applications.Herein,we present a cascaded electron transition pathway in a ternary heterostructure consisting of CdS quantum dots,carbon dots(CDs)and CuWO4 hollow spheres,which proves to greatly facilitate the photogenerated electron-hole separation,and eventually boosts the degradation efficiency of phenol and congo red by 100%and 46%compared to bare CuWO4.The enhanced performance of the CuWO4/CdS/CDs heterostructure mainly originates from the unidirectional electron migration from CdS to CuWO4 and then to the organics through CDs.This work elucidates the electron transfer kinetics in multi-phase system and provides a new design paradigm for optimizing the properties of CuWO4 based photocatalysts.
基金supported by the National Basic Research Program of China (973 Program, 2013CB632404)National Natural Science Foundation of China (21473090 and 51272102)a Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions
文摘CuW（1-x）MoxO4 solid solution of CuWO4 and CuMoO4, which is a copper-based multi-component oxide semiconductor, possesses much narrower band gap than CuWO4. In theory, it can absorb a larger part of the visible spectrum, widening the use of solar spectroscopy and obtaining a higher photo-to-chemical conversion efficiency. In this study, CuW（1-x）MoxO4 thin-film photoanodes on conducting glass were prepared using a simple and low-cost spray pyrolysis method. The resulting CuW（1-x）MoxO4 photoanodes perform higher photocurrent than CuWO4 photoanodes under AM 1.5 G simulated sunlight illumination（100 m W cm^（-2））in 0.1 mol L^（-1） phosphate buffer at pH 7. Combined with IPCE and Mott-Schottky analysis, the enhancement of the photocurrent is due to the improvement of photon utilization and the increase of carrier concentration with the incorporation of Mo atoms. Moreover, with the optimal Mo/W atomic ratio,the photocurrent density increases obviously from 0.07 to 0.46 m A cm^（-2） at 1.23 V（RHE） bias. In addition, compared with particle-assembled thin-film photoanodes prepared by solidphase reaction and drop-necking treatment, the photoanodes prepared by spray pyrolysis have obvious advantages in terms of reducing resistance and facilitating charge transport.
