A visible light-induced, Cu-doped BiVO_4 photocatalyst was synthesized by a microwave hydrothermal method. The photocatalytic efficiency was investigated in the degradation of model water pollutants like Methylene Blu...A visible light-induced, Cu-doped BiVO_4 photocatalyst was synthesized by a microwave hydrothermal method. The photocatalytic efficiency was investigated in the degradation of model water pollutants like Methylene Blue(dye) and ibuprofen(pharmaceuticals), as well as the inactivation of Escherichia coli(bacteria). The Cu-doped BiVO4 samples showed better efficiency than undoped BiVO_4, and the 1 wt.% Cu-doped BiVO_4 sample showed the best efficiency. The degradation of Methylene Blue reached 95%, while the degradation of ibuprofen reached 75%, and the inactivation of E. coli reached 85% in irradiation with visible light. The appearance of additional absorption band shoulders and widening of the optical absorption in the visible range makes the prepared powder an efficient visible light-driven photocatalyst. Moreover, the formation of an in-gap energy state just above the valance band as determined by density functional theory(DFT) first principle calculation, facilitates the wider optical absorption range of the doped system. Similarly, this in-gap energy state also acts as an electron trap, which is favorable for the efficient separation and photoexcited charge carriers' transfer process. The formation of oxygen vacancies due to doping also improved the separation of the charge carrier, which promoted the trapping of electrons and inhibited electron hole recombination, thus increasing the photocatalytic activity. No decrease in the efficiency of the 1 wt.% Cu-doped BiVO_4 photocatalyst in the degradation of ibuprofen over three consecutive cycles revealed the stability of the photocatalyst towards photocorrosion. These findings highlight the multifunctional applications of Cu-doped BiVO_4 in wastewater containing multiple pollutants.展开更多
A BiVO_4 photoanode with exposed(040) facets was prepared to enhance its photoelectrochemical performance.The exposure of the(040) crystal planes of the BiVO_4 film was induced by adding NaCl to the precursor solution...A BiVO_4 photoanode with exposed(040) facets was prepared to enhance its photoelectrochemical performance.The exposure of the(040) crystal planes of the BiVO_4 film was induced by adding NaCl to the precursor solution. The asprepared BiVO_4 photoanode exhibits higher solar-light absorption and charge-separation efficiency compared to those of an anode prepared without adding Na Cl. To our knowledge,the photocurrent density(1.26 m A cm^(-2) at 1.23 V vs. RHE) of as-prepared BiVO_4 photoanode is the highest according to the reports for bare BiVO_4 films under simulated AM1.5 G solar light, and the incident photon-to-current conversion efficiency is above 35% at 400 nm. The photoelectrochemical(PEC)water-splitting performance was also dramatically improvedwith a hydrogen evolution rate of 9.11 lmol cm^(-2) h^(-1), which is five times compared with the BiVO_4 photoanode prepared without NaCl(1.82 lmol cm^(-2) h^(-1)). Intensity-modulated photocurrent spectroscopy and transient photocurrent measurements show a higher charge-carrier-transfer rate for this photoanode. These results demonstrate a promising approach for the development of high-performance BiVO_4 photoanodes which can be used for efficient PEC water splitting and degradation of organic pollutants.展开更多
Porous hollow microspheres of bismuth vanadate(BiVO_4) were successfully synthesized with the assistances of ethylenediamine tetraacetic(EDTA) and sodium dodecylbenzene sulfonate(SDBS) via hydrothermal method.The as-p...Porous hollow microspheres of bismuth vanadate(BiVO_4) were successfully synthesized with the assistances of ethylenediamine tetraacetic(EDTA) and sodium dodecylbenzene sulfonate(SDBS) via hydrothermal method.The as-prepared BiVO_4 samples were characterized by X-ray diffraction(XRD),field-emission scanning electron microscopy(FE-SEM) and UV-vis diffuse reflectance spectra(DRS).It was found that the ratio of EDTA and SDBS had a significant impact on the crystalline structure,size and morphology of BiVO_4 photocatalyst.The crystal phase could be adjusted by changing the mass ratio of EDTA and SDBS.The photocatalytic activities of different BiVO_4 samples were investigated through the degradation of RhB in the presence of H_2O_2 under visible light irradiation.The results indicated that the photocatalytic performance of the BiVO_4 microstructures was greatly influenced by the porous structure,morphology and band gap.The BiVO_4 sample prepared with the EDTA and SDBS ratio of 2:1 and total amount of 1.5 g have shown superior photocatalytic performance for its unique morphology,good porous structure and low band gap energy.展开更多
萃取催化氧化脱硫(ECODS)技术因具有反应条件温和、成本低、绿色经济等优势,已成为目前研究人员关注的热点。为了开发温和条件下的高效催化剂,采用静电纺丝技术制备了磷钨酸(H3PW_(12)O_(40),简称PW_(12))负载的BiVO_(4)纳米纤维催化剂...萃取催化氧化脱硫(ECODS)技术因具有反应条件温和、成本低、绿色经济等优势,已成为目前研究人员关注的热点。为了开发温和条件下的高效催化剂,采用静电纺丝技术制备了磷钨酸(H3PW_(12)O_(40),简称PW_(12))负载的BiVO_(4)纳米纤维催化剂,通过X射线衍射光谱(XRD)、傅里叶红外光谱(FT-IR)、扫描电镜(SEM)、透射电镜(TEM)、电感耦合等离子体(ICP)、X射线光电子能谱(XPS)等手段对催化剂的结构、形貌和组成进行分析,并将此催化剂应用于ECODS中评价其脱硫性能。结果表明:通过静电纺丝技术成功实现了PW_(12)在BiVO_(4)纳米纤维上的均匀分散;在反应温度为60℃、氧/硫摩尔比为6/1、[Bmim]PF_(6)为萃取剂的条件下,使用0.02 g 6%PW_(12)/BiVO_(4)纳米纤维催化剂在40 min内脱硫效率能达到90.4%,且该催化剂具有良好的循环性能。展开更多
Doping metal ions offer a promising strategy to tune the intrinsic and surface properties of BiVO_(4)for enhanced photoelectrochemical(PEC)activity.Given this,experimental and theoretical studies on cadmium(Cd)doping ...Doping metal ions offer a promising strategy to tune the intrinsic and surface properties of BiVO_(4)for enhanced photoelectrochemical(PEC)activity.Given this,experimental and theoretical studies on cadmium(Cd)doping to BiVO_(4)photoanode were studied for PEC water splitting applications.The spectroscopic and PEC results indicate that the substitution of Cd at Bi lattice sites causes the reduction in the valence state of V^(5+)to V4+that creates hole trap states below the Fermi level of BiVO_(4).The introduced hole trap states at the BiVO_(4)surface suppress the charge recombination and provide effective hole transfer sites for the facile water oxidation reactions.The CdBiVO_(4)exhibited significantly higher photocurrent compared to the pristine BiVO_(4)reaching 3.5 mA cm^(-2)(with a hole scavenger)at 1.23 V vs RHE.Furthermore,doping increases the carrier density in the bulk of BiVO_(4)leading to improved charge separation,and charge transfer while reducing the hole transfer resistance at the interface.The Cd-doped BiVO_(4)exhibited a charge separation efficiency of 80%and with a 90%of overall water splitting faradaic efficiency.Importantly,the results of this work propose the advantages of doping metal ions at Bi lattice sites in BiVO_(4)for improved PEC activity.展开更多
Highly active and stable FeOOH cocatalysts are essential for achieving optimal performance of BiVO_(4)(BVO)photoanodes.Despite offering remarkable structural stability,widely used thick FeOOH cocatalysts often suffer ...Highly active and stable FeOOH cocatalysts are essential for achieving optimal performance of BiVO_(4)(BVO)photoanodes.Despite offering remarkable structural stability,widely used thick FeOOH cocatalysts often suffer from insufficient hole transport capability,which hinders the overall activity.The present study demonstrates that a simple photoetching strategy is able to introduce gradient distributed oxygen vacancies(GO_(V))in the thick FeOOH layer and significantly enhances the photogenerated holes transport dynamics.The incorporation of GO_(V)within FeOOH not only realizes the“relay transport”of photogenerated hole through the progressive upward shift of the valence band in the spatial distribution,but also provides abundant oxidation active sites by efficient hole trapping.These improvements effectively improve the oxygen evolution reaction(OER)activities and mitigate photocorrosion by the instantaneous hole extraction.Consequently,the FeOOH-GO_(V)layer enables the BVO/FeOOH-GO_(V)photoanode to achieve an impressive photocurrent density of 5.37 mA cm^(-2)and a robust operational stability up to 160 h at 1.23 VRHE,setting new benchmarks for current density and stability in FeOOH-based BVO photoanodes.This work provides an effective avenue to optimize OER cocatalysts for constructing highly efficient and stable photoelectrochemical water splitting devices.展开更多
Efficient solar light harvesting is essential for high-performance photocatalysts.Here,Rigorous CoupledWave Analysis(RCWA)computational method is used to investigate and optimize the optical absorption of TiO_(2)-BiVO...Efficient solar light harvesting is essential for high-performance photocatalysts.Here,Rigorous CoupledWave Analysis(RCWA)computational method is used to investigate and optimize the optical absorption of TiO_(2)-BiVO_(4) inverse opal(IO)structures under varying light incidence angles and pore-filling medium(air or water).Simulations were validated against experimental reflectance data.They revealed that small-pore IOs strongly absorb in the UV-C and UV-B regions due to the slow photon effect,making them ideal for sterilization and water disinfection.Medium-and large-pore IOs benefit from additional slow photon effect at the 2nd order photonic band gap,enhancing absorption across both UV and visible regions.Medium-pore IOs are suited for indoor air treatment and water purification,while large-pore IOs with the highest photon flux enhancement enable solar-driven photocatalysis such as outdoor pollutant removal and hydrogen production.For all tested IO designs,the absorbed photon flux exceeds that of equivalent planar slabs,highlighting the advantage of photonic structuring for sustainable photocatalytic applications.展开更多
In this study, we report the facile fabrication of a carbon quantum dots(CQDs)/BiVO_4 composite with efficient photocatalytic activity. Due to the excellent upconversion photoluminescence, as well as the photo-induced...In this study, we report the facile fabrication of a carbon quantum dots(CQDs)/BiVO_4 composite with efficient photocatalytic activity. Due to the excellent upconversion photoluminescence, as well as the photo-induced electron transfer and reservoir properties of CQDs, the CQDs/BiVO_4 composite exhibited superior photocatalytic performance in the degradation of rhodamine B(RhB) under the irradiation of simulated solar light. This study provides a strategy for the development of high-performance catalysts based on CQDs.展开更多
基金supported by the Global Research Laboratory Program of the National Research Foundation of Korea (NRF)funded by the Ministry of Education,Science and Technology (MEST) of Korea (No.2010-00339)
文摘A visible light-induced, Cu-doped BiVO_4 photocatalyst was synthesized by a microwave hydrothermal method. The photocatalytic efficiency was investigated in the degradation of model water pollutants like Methylene Blue(dye) and ibuprofen(pharmaceuticals), as well as the inactivation of Escherichia coli(bacteria). The Cu-doped BiVO4 samples showed better efficiency than undoped BiVO_4, and the 1 wt.% Cu-doped BiVO_4 sample showed the best efficiency. The degradation of Methylene Blue reached 95%, while the degradation of ibuprofen reached 75%, and the inactivation of E. coli reached 85% in irradiation with visible light. The appearance of additional absorption band shoulders and widening of the optical absorption in the visible range makes the prepared powder an efficient visible light-driven photocatalyst. Moreover, the formation of an in-gap energy state just above the valance band as determined by density functional theory(DFT) first principle calculation, facilitates the wider optical absorption range of the doped system. Similarly, this in-gap energy state also acts as an electron trap, which is favorable for the efficient separation and photoexcited charge carriers' transfer process. The formation of oxygen vacancies due to doping also improved the separation of the charge carrier, which promoted the trapping of electrons and inhibited electron hole recombination, thus increasing the photocatalytic activity. No decrease in the efficiency of the 1 wt.% Cu-doped BiVO_4 photocatalyst in the degradation of ibuprofen over three consecutive cycles revealed the stability of the photocatalyst towards photocorrosion. These findings highlight the multifunctional applications of Cu-doped BiVO_4 in wastewater containing multiple pollutants.
基金financial support provided by the National Nature Science Foundation of China(No.21576162,No.51578332,and No.21507085)the Shanghai Yangfan Program(14YF1401500)
文摘A BiVO_4 photoanode with exposed(040) facets was prepared to enhance its photoelectrochemical performance.The exposure of the(040) crystal planes of the BiVO_4 film was induced by adding NaCl to the precursor solution. The asprepared BiVO_4 photoanode exhibits higher solar-light absorption and charge-separation efficiency compared to those of an anode prepared without adding Na Cl. To our knowledge,the photocurrent density(1.26 m A cm^(-2) at 1.23 V vs. RHE) of as-prepared BiVO_4 photoanode is the highest according to the reports for bare BiVO_4 films under simulated AM1.5 G solar light, and the incident photon-to-current conversion efficiency is above 35% at 400 nm. The photoelectrochemical(PEC)water-splitting performance was also dramatically improvedwith a hydrogen evolution rate of 9.11 lmol cm^(-2) h^(-1), which is five times compared with the BiVO_4 photoanode prepared without NaCl(1.82 lmol cm^(-2) h^(-1)). Intensity-modulated photocurrent spectroscopy and transient photocurrent measurements show a higher charge-carrier-transfer rate for this photoanode. These results demonstrate a promising approach for the development of high-performance BiVO_4 photoanodes which can be used for efficient PEC water splitting and degradation of organic pollutants.
基金National Natural Science Foundations of China(Nos.51178093,51208086)Central University Project,China(No.2232013D3-10)
文摘Porous hollow microspheres of bismuth vanadate(BiVO_4) were successfully synthesized with the assistances of ethylenediamine tetraacetic(EDTA) and sodium dodecylbenzene sulfonate(SDBS) via hydrothermal method.The as-prepared BiVO_4 samples were characterized by X-ray diffraction(XRD),field-emission scanning electron microscopy(FE-SEM) and UV-vis diffuse reflectance spectra(DRS).It was found that the ratio of EDTA and SDBS had a significant impact on the crystalline structure,size and morphology of BiVO_4 photocatalyst.The crystal phase could be adjusted by changing the mass ratio of EDTA and SDBS.The photocatalytic activities of different BiVO_4 samples were investigated through the degradation of RhB in the presence of H_2O_2 under visible light irradiation.The results indicated that the photocatalytic performance of the BiVO_4 microstructures was greatly influenced by the porous structure,morphology and band gap.The BiVO_4 sample prepared with the EDTA and SDBS ratio of 2:1 and total amount of 1.5 g have shown superior photocatalytic performance for its unique morphology,good porous structure and low band gap energy.
文摘萃取催化氧化脱硫(ECODS)技术因具有反应条件温和、成本低、绿色经济等优势,已成为目前研究人员关注的热点。为了开发温和条件下的高效催化剂,采用静电纺丝技术制备了磷钨酸(H3PW_(12)O_(40),简称PW_(12))负载的BiVO_(4)纳米纤维催化剂,通过X射线衍射光谱(XRD)、傅里叶红外光谱(FT-IR)、扫描电镜(SEM)、透射电镜(TEM)、电感耦合等离子体(ICP)、X射线光电子能谱(XPS)等手段对催化剂的结构、形貌和组成进行分析,并将此催化剂应用于ECODS中评价其脱硫性能。结果表明:通过静电纺丝技术成功实现了PW_(12)在BiVO_(4)纳米纤维上的均匀分散;在反应温度为60℃、氧/硫摩尔比为6/1、[Bmim]PF_(6)为萃取剂的条件下,使用0.02 g 6%PW_(12)/BiVO_(4)纳米纤维催化剂在40 min内脱硫效率能达到90.4%,且该催化剂具有良好的循环性能。
基金the support of the Natural Sciences and Engineering Research Council of Canada(NSERC)Tier 1 Canada Research Chair in Green Hydrogen Production,the Québec Ministère de l'Économie,de l'Innovation et de l'Énergie(MEIE)[Développement de catalyseurs et d'électrodes innovants,àfaibles coûts,performants et durables pour la production d'hydrogène vert,funding reference number 00393501]。
文摘Doping metal ions offer a promising strategy to tune the intrinsic and surface properties of BiVO_(4)for enhanced photoelectrochemical(PEC)activity.Given this,experimental and theoretical studies on cadmium(Cd)doping to BiVO_(4)photoanode were studied for PEC water splitting applications.The spectroscopic and PEC results indicate that the substitution of Cd at Bi lattice sites causes the reduction in the valence state of V^(5+)to V4+that creates hole trap states below the Fermi level of BiVO_(4).The introduced hole trap states at the BiVO_(4)surface suppress the charge recombination and provide effective hole transfer sites for the facile water oxidation reactions.The CdBiVO_(4)exhibited significantly higher photocurrent compared to the pristine BiVO_(4)reaching 3.5 mA cm^(-2)(with a hole scavenger)at 1.23 V vs RHE.Furthermore,doping increases the carrier density in the bulk of BiVO_(4)leading to improved charge separation,and charge transfer while reducing the hole transfer resistance at the interface.The Cd-doped BiVO_(4)exhibited a charge separation efficiency of 80%and with a 90%of overall water splitting faradaic efficiency.Importantly,the results of this work propose the advantages of doping metal ions at Bi lattice sites in BiVO_(4)for improved PEC activity.
基金supported by the State Key Laboratory of Solidification Processing in NWPU(SKLSP202407)the National Natural Science Foundation of China(52402130)+2 种基金the Natural Science Basis Research Plan in Shaanxi Province of China(2024JC-YBQN-0384)the Shaanxi Science and Technology Innovation Team(2023-CX-TD-44)the National Natural Science Foundation of China(52301015).
文摘Highly active and stable FeOOH cocatalysts are essential for achieving optimal performance of BiVO_(4)(BVO)photoanodes.Despite offering remarkable structural stability,widely used thick FeOOH cocatalysts often suffer from insufficient hole transport capability,which hinders the overall activity.The present study demonstrates that a simple photoetching strategy is able to introduce gradient distributed oxygen vacancies(GO_(V))in the thick FeOOH layer and significantly enhances the photogenerated holes transport dynamics.The incorporation of GO_(V)within FeOOH not only realizes the“relay transport”of photogenerated hole through the progressive upward shift of the valence band in the spatial distribution,but also provides abundant oxidation active sites by efficient hole trapping.These improvements effectively improve the oxygen evolution reaction(OER)activities and mitigate photocorrosion by the instantaneous hole extraction.Consequently,the FeOOH-GO_(V)layer enables the BVO/FeOOH-GO_(V)photoanode to achieve an impressive photocurrent density of 5.37 mA cm^(-2)and a robust operational stability up to 160 h at 1.23 VRHE,setting new benchmarks for current density and stability in FeOOH-based BVO photoanodes.This work provides an effective avenue to optimize OER cocatalysts for constructing highly efficient and stable photoelectrochemical water splitting devices.
基金supported by the FNRS-FRFC,the Walloon Region,and the University of Namur(Conventions No.2.5020.11,GEQ U.G006.15,1610468,RW/GEQ2016 et U.G011.22)funding from the European Union’s Horizon 2020 research and innovation program under the Marie Sklodowska Curie grant agreement n°101034383。
文摘Efficient solar light harvesting is essential for high-performance photocatalysts.Here,Rigorous CoupledWave Analysis(RCWA)computational method is used to investigate and optimize the optical absorption of TiO_(2)-BiVO_(4) inverse opal(IO)structures under varying light incidence angles and pore-filling medium(air or water).Simulations were validated against experimental reflectance data.They revealed that small-pore IOs strongly absorb in the UV-C and UV-B regions due to the slow photon effect,making them ideal for sterilization and water disinfection.Medium-and large-pore IOs benefit from additional slow photon effect at the 2nd order photonic band gap,enhancing absorption across both UV and visible regions.Medium-pore IOs are suited for indoor air treatment and water purification,while large-pore IOs with the highest photon flux enhancement enable solar-driven photocatalysis such as outdoor pollutant removal and hydrogen production.For all tested IO designs,the absorbed photon flux exceeds that of equivalent planar slabs,highlighting the advantage of photonic structuring for sustainable photocatalytic applications.
基金supported by the National Natural Science Foundation of China(Grant Nos.51402194,51572128)
文摘In this study, we report the facile fabrication of a carbon quantum dots(CQDs)/BiVO_4 composite with efficient photocatalytic activity. Due to the excellent upconversion photoluminescence, as well as the photo-induced electron transfer and reservoir properties of CQDs, the CQDs/BiVO_4 composite exhibited superior photocatalytic performance in the degradation of rhodamine B(RhB) under the irradiation of simulated solar light. This study provides a strategy for the development of high-performance catalysts based on CQDs.
