The Fe_(1−x)Ni_(x)VO_(4)(x=0,0.05,0.10,and 0.20)nanoparticles in this work were successfully synthesized via a co-precipitation method.The structural,magnetic and electrochemical properties of the prepared Fe_(1−x)Ni_...The Fe_(1−x)Ni_(x)VO_(4)(x=0,0.05,0.10,and 0.20)nanoparticles in this work were successfully synthesized via a co-precipitation method.The structural,magnetic and electrochemical properties of the prepared Fe_(1−x)Ni_(x)VO_(4) nanoparticles were studied as a function of Ni content.The experimental results show that the prepared Ni-doped FeVO_(4) samples have a triclinic structure.Scanning electron microscopy(SEM)images reveal a decrease in average nanoparticle size with increasing Ni content,leading to an enhancement in both specific surface area and magnetization values.X-ray absorption near edge structure(XANES)analysis confirms the substitution of Ni^(2+)ions into Fe^(3+)sites.The magnetic investigation reveals that Ni-doped FeVO_(4) exhibits weak ferromagnetic behavior at room temperature,in contrast to the antiferromagnetic behavior observed in the undoped FeVO_(4).Electrochemical studies demonstrate that the Fe_(0.95)Ni_(0.05)VO_(4) electrode achieves the highest specific capacitance of 334.05 F·g^(−1) at a current density of 1 A·g^(−1),which is attributed to its smallest average pore diameter.In addition,the enhanced specific surface of the Fe_(0.8)Ni_(0.2)VO_(4) electrode is responsible for its outstanding cyclic stability.Overall,our results suggest that the magnetic and electrochemical properties of FeVO_(4) nanoparticles could be effectively tuned by varying Ni doping contents.展开更多
Developing a low-cost stable and high-performance peroxymonosulfate(PMS)catalyst to degrade refractory organic pollutants is still an urgent problem.Herein,this study reported FeVO_(4)nanorods decorated sepiolite(FeVO...Developing a low-cost stable and high-performance peroxymonosulfate(PMS)catalyst to degrade refractory organic pollutants is still an urgent problem.Herein,this study reported FeVO_(4)nanorods decorated sepiolite(FeVO_(4)/sepiolite)through simple hydrothermal method as an adsorptive-catalyst for PMS activation to degrade tetracycline(TC).Benefiting from the introduction of sepiolite support,FeVO_(4)nanorods could be uniformly immobilized onto fibrous sepiolite surface.As a result,FeVO_(4)/sepiolite composite was endowed with excellent adsorption properties,rich surface hydroxyl groups,more reaction active sites,and the stable redox cycle of Fe^(3+)/Fe^(2+)and V5^(+)/V4^(+).Therefore,higher TC degradation efficiency(91.19%within 40 min)and larger reaction rate constant(0.1649 min^(-1))were obtained in FeVO_(4)/sepiolite/PMS system than in FeVO_(4)/PMS system.Besides,the composite presented good stability and reusability,and the effects of application parameters on TC degradation were investigated in detail.Through quenching experiment and electron paramagentic resonance(EPR)test,it was found that both radical and non-radical species participates in TC degradation,and ^(1)O_(2) were the main active species.The PMS activation mechanism was proposed,and the possible degradation pathway was also analyzed according to the high performance liquid chromatography-mass spectrometry(HPLC-MS)results.Overall,this work provides meaningful insights for designing natural mineral based PMS activators to effectively remediate antibiotic wastewater.展开更多
Synergistic effect of FeVO_4 withα-Fe_2O_3 was found in Fe-V-O catalyst,which was responsible for the high apparent formation rate（A.F.R.） of benzaldehyde in liquid phase oxidation of toluene by hydrogen peroxide.T...Synergistic effect of FeVO_4 withα-Fe_2O_3 was found in Fe-V-O catalyst,which was responsible for the high apparent formation rate（A.F.R.） of benzaldehyde in liquid phase oxidation of toluene by hydrogen peroxide.The synergistic effect might create VO_πspecies as active sites;moreover,it improved the reducibility and the reactivity of Fe-V-O catalyst.In order to gain the high A.F.R. of benzaldehyde,the catalyst should have the moderate reducibihty.展开更多
Developing deNO_(x)catalysts with lower activity temperatures range significantly reduces NH_(3)selective catalytic reduction(SCR)operating costs for low-temperature industrial flue gases.Herein,a novel FeVO_(4)/CeO_(...Developing deNO_(x)catalysts with lower activity temperatures range significantly reduces NH_(3)selective catalytic reduction(SCR)operating costs for low-temperature industrial flue gases.Herein,a novel FeVO_(4)/CeO_(2)catalyst with great low-temperature NH_(3)-SCR and nitrogen selectivity was synthesized using a dipping method.Characterization techniques such as X-ray diffraction,Raman spectroscopy,specific surface and porosity analysis,H2 temperature-programmed reduction,NH_(3)temperature-programmed desorption,X-ray photoelectron spectroscopy,and the in situ diffused reflectance infrared Fourier transform spectroscopy were used to investigate the catalytic mechanism.An appropriate addition for FeVO_(4)in the catalyst was 5 wt.%from the results,and the active substance content reached the maximum dispersal capacity of the carrier.The NO_(x)conversion exceeded 90%,and the nitrogen selectivity was more than 98%over this catalyst at 200–350℃.The activity was kept at 88%after 7.5 h of reaction at 200℃ for 7.5 h in 35 mg m^(-3)SO_(2)gas.The remarkable deNO_(x)activity,nitrogen selectivity,and sulphur resistance performances are attributed to the low redox temperature,the abundance of medium-strong acid and strong acid sites,the sufficient adsorbed oxygen,and the superior Fe^(2+)content on the surface.The Langmuir–Hinshelwood mechanism was observed on the FeVO_(4)/CeO_(2)catalyst in the NH_(3)selective catalytic reduction of NO_(x).展开更多
Elemental doping of BiVO_(4) crystal lattices effectively enhances carrier separation,thereby facilitating efficient photoelectrochemical water splitting.However,the positive effect of elementally induced lattice dist...Elemental doping of BiVO_(4) crystal lattices effectively enhances carrier separation,thereby facilitating efficient photoelectrochemical water splitting.However,the positive effect of elementally induced lattice distortions on hole extraction has been neglected.Herein,the crystal lattice of BiVO_(4) is distorted by doping with an inexpensive Cs metal;then,CoFe_(2)O_(4) is used as an efficient hole-extraction layer to further modify the surface of the doped photoanode.Benefiting from the above design,the newly prepared CoFe_(2)O_(4)-Cs-BiVO_(4) photoanode achieved a photocurrent density of 5.66 mA cm^(–2) at 1.23 V vs.a reversible hydrogen electrode,indicating a 3.9-fold improvement in photocurrent density.Detailed physicochemical characterization and density functional theory calculations showed that the lattice distortion induced by Cs doping promoted the directional migration of BiVO_(4) bulk-phase holes to the CoFe_(2)O_(4) layer.Additionally,the coupled CoFe_(2)O_(4) can be used as a hole extraction layer to further enhance the interfacial migration of carriers.The synergistic effect of the two effectively promotes the directional migration of photogenerated carriers from the BiVO_(4) bulk phase to the active sites of the oxygen evolution reaction,thereby effectively inhibiting carrier recombination.This study revealed the positive effect of the dual-hole extraction strategy on solar energy conversion,thereby opening new avenues for the rational design of photoanodes.展开更多
Given the advantages of being abundant in resources,environmental benign and highly safe,rechargeable zinc-ion batteries(ZIBs)enter the global spotlight for their potential utilization in large-scale energy storage.De...Given the advantages of being abundant in resources,environmental benign and highly safe,rechargeable zinc-ion batteries(ZIBs)enter the global spotlight for their potential utilization in large-scale energy storage.Despite their preliminary success,zinc-ion storage that is able to deliver capacity>400 mAh g^-1 remains a great challenge.Here,we demonstrate the viability of NH4V4O10(NVO)as high-capacity cathode that breaks through the bottleneck of ZIBs in limited capacity.The first-principles calculations reveal that layered NVO is a good host to provide fast Zn^2+ions diffusion channel along its[010]direction in the interlayer space.On the other hand,to further enhance Zn^2+ion intercalation kinetics and long-term cycling stability,a three-dimensional(3D)flower-like architecture that is self-assembled by NVO nanobelts(3D-NVO)is rationally designed and fabricated through a microwave-assisted hydrothermal method.As a result,such 3D-NVO cathode possesses high capacity(485 mAh g^-1)and superior long-term cycling performance(3000 times)at 10 A g^-1(~50 s to full discharge/charge).Additionally,based on the excellent 3D-NVO cathode,a quasi-solid-state ZIB with capacity of 378 mAh g^-1is developed.展开更多
Photoelectrochemical(PEC)technology is considered to be a promising approach for solar-driven hydrogen production with zero emissions.Bismuth vanadate(BiVO_(4))is a kind of photocatalytic material with strong photoact...Photoelectrochemical(PEC)technology is considered to be a promising approach for solar-driven hydrogen production with zero emissions.Bismuth vanadate(BiVO_(4))is a kind of photocatalytic material with strong photoactivity in the visible light region and appropriate band gap for PEC water splitting.However,the solar-to-hydrogen efficiency(STH)of BiVO_(4)is far away from the 10%target needed for practical application due to its poor charge separation ability.Therefore,this review attempts to summarize the strategies for improving the photocurrent density and especially hydrogen production of BiVO_(4)materials through PEC techniques in the last three years,such as doping nonmetal and metal elements,depositing noble metals,constructing heterojunctions,coupling with carbon and metalorganic framework(MOF)materials to further enhance the PEC performance of BiVO_(4)photoanode.This review aims to serve as a general guideline to fabricate highly efficient BiVO_(4)-based materials for PEC water splitting.展开更多
We report a photoelectrochemical investigation of BiVO4 photoanodes prepared by successive ionic layer adsorption and reaction(SILAR),a facile method that yields uniform nanoporous films.After characterization of the ...We report a photoelectrochemical investigation of BiVO4 photoanodes prepared by successive ionic layer adsorption and reaction(SILAR),a facile method that yields uniform nanoporous films.After characterization of the phase,morphology,composition,and optical properties of the prepared films,the efficiencies of charge separation(ηsep)and water oxidation(ηox)in solar water splitting cells employing these photoanodes were estimated following a previously reported procedure.Unexpected wavelength and illumination direction dependencies were discovered in the derived efficiencies,casting doubt on the validity of the analysis.An alternative approach using a diffusion–reaction model that explicitly considers the efficiency of electron collection resolved the discrepancies and explained the illumination direction dependence of the photocurrent.Electron diffusion lengths(Ln)of 0.45μm and 0.55μm were derived for pristine and cobalt phosphate(Co-Pi)modified BiVO4,respectively,which are much shorter than the film thickness of^2.1μm.The Co-Pi treatment also increasedηoxfrom 0.86 to^1,which is the main reason for the overall performance enhancement caused by adding Co-Pi.These findings suggest that there is little scope for improving the performance of SILAR-deposited BiVO4 photoanodes by further catalyzing water oxidation,but enhanced performance is achievable if electron transport can be improved.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
As global energy demand continues to rise with fossil fuels dwindling at a faster rate,posing energy and environmental concerns,there is a growing interest in exploring alternative,green,and renewable energy sources.A...As global energy demand continues to rise with fossil fuels dwindling at a faster rate,posing energy and environmental concerns,there is a growing interest in exploring alternative,green,and renewable energy sources.Ammonia is a key hydrogen energy carrier and precursor to many value-added products,and the efforts for its generation at commercial scale using greener methods are intensifying to mitigate the reliance on the energy-intensive Haber-Bosch process.The electrochemical nitrogen reduction reaction(e-NRR)is a highly promising way of synthesizing ammonia under energy-efficient,green,and ambient conditions.Despite its attractive potential,the activity and efficiency of conventional e-NRR catalysts are still a major concern due to low selectivity and poor ammonia yields.Inspired by the FeFe and FeV cofactors present in nitrogenases,this study reports the synthesis and electrocatalytic evaluation of FeVO_(4)catalyst for N_(2)reduction.The FeVO_(4)nanoparticles anchored on Fe foam(FF)could serve as an efficient electrocatalyst for the electrochemical nitrogen fixation,achieving a significant performance with highest NH_(3)yield of 22.5μg·h^(-1)·mg^(-1)and Faradaic efficiency(FE)of 20.74%at-0.2 VRHE in 0.1 M Na_(2)SO_(4).The FeVO_(4)electrocatalyst exhibited robust electrochemical stability for 24 h of operation at-0.2 VRHE.The high catalytic performance originated from the synergistic interactions between Fe and V which serve as dual electron donation centers for effective e-NRR.Furthermore,the coupling interaction between FeVO_(4)and FF support exposed abundant intrinsic active sites and facilitated beneficial charge transfer further inducing superior e-NRR activity.Density functional theory(DFT)computations disclosed that surface Fe atoms are the main active centers for e-NRR which proceed via the alternating pathway.展开更多
文摘The Fe_(1−x)Ni_(x)VO_(4)(x=0,0.05,0.10,and 0.20)nanoparticles in this work were successfully synthesized via a co-precipitation method.The structural,magnetic and electrochemical properties of the prepared Fe_(1−x)Ni_(x)VO_(4) nanoparticles were studied as a function of Ni content.The experimental results show that the prepared Ni-doped FeVO_(4) samples have a triclinic structure.Scanning electron microscopy(SEM)images reveal a decrease in average nanoparticle size with increasing Ni content,leading to an enhancement in both specific surface area and magnetization values.X-ray absorption near edge structure(XANES)analysis confirms the substitution of Ni^(2+)ions into Fe^(3+)sites.The magnetic investigation reveals that Ni-doped FeVO_(4) exhibits weak ferromagnetic behavior at room temperature,in contrast to the antiferromagnetic behavior observed in the undoped FeVO_(4).Electrochemical studies demonstrate that the Fe_(0.95)Ni_(0.05)VO_(4) electrode achieves the highest specific capacitance of 334.05 F·g^(−1) at a current density of 1 A·g^(−1),which is attributed to its smallest average pore diameter.In addition,the enhanced specific surface of the Fe_(0.8)Ni_(0.2)VO_(4) electrode is responsible for its outstanding cyclic stability.Overall,our results suggest that the magnetic and electrochemical properties of FeVO_(4) nanoparticles could be effectively tuned by varying Ni doping contents.
基金Project(23-2-1-107-zyyd-jch)supported by the Qingdao Natural Science Foundation,ChinaProject(ZR2022QE236)supported by the Natural Science Foundation of Shandong Province Youth Project,China+2 种基金Project(SDCX-ZG-202400211,SDCX-ZG-202203052)supported by the Shandong Postdoctoral Science Foundation,ChinaProject(ZD2023K03)supported by the Engineering Research Center of Non-metallic Minerals of Zhejiang Province,ChinaProject(01020240806)supported by the Qingdao Postdoctoral Program for Applied Research,China。
文摘Developing a low-cost stable and high-performance peroxymonosulfate(PMS)catalyst to degrade refractory organic pollutants is still an urgent problem.Herein,this study reported FeVO_(4)nanorods decorated sepiolite(FeVO_(4)/sepiolite)through simple hydrothermal method as an adsorptive-catalyst for PMS activation to degrade tetracycline(TC).Benefiting from the introduction of sepiolite support,FeVO_(4)nanorods could be uniformly immobilized onto fibrous sepiolite surface.As a result,FeVO_(4)/sepiolite composite was endowed with excellent adsorption properties,rich surface hydroxyl groups,more reaction active sites,and the stable redox cycle of Fe^(3+)/Fe^(2+)and V5^(+)/V4^(+).Therefore,higher TC degradation efficiency(91.19%within 40 min)and larger reaction rate constant(0.1649 min^(-1))were obtained in FeVO_(4)/sepiolite/PMS system than in FeVO_(4)/PMS system.Besides,the composite presented good stability and reusability,and the effects of application parameters on TC degradation were investigated in detail.Through quenching experiment and electron paramagentic resonance(EPR)test,it was found that both radical and non-radical species participates in TC degradation,and ^(1)O_(2) were the main active species.The PMS activation mechanism was proposed,and the possible degradation pathway was also analyzed according to the high performance liquid chromatography-mass spectrometry(HPLC-MS)results.Overall,this work provides meaningful insights for designing natural mineral based PMS activators to effectively remediate antibiotic wastewater.
基金supported by Ministry of Education(NoNCET-10-878,20096101120018,2009-37th of SRFROCS)Shaanxi Province(No2009ZDKG-70,09JK793)+1 种基金Northwest University(NoPR09005,10YSY08)State Key Lab for SSPC(2009)
文摘Synergistic effect of FeVO_4 withα-Fe_2O_3 was found in Fe-V-O catalyst,which was responsible for the high apparent formation rate（A.F.R.） of benzaldehyde in liquid phase oxidation of toluene by hydrogen peroxide.The synergistic effect might create VO_πspecies as active sites;moreover,it improved the reducibility and the reactivity of Fe-V-O catalyst.In order to gain the high A.F.R. of benzaldehyde,the catalyst should have the moderate reducibihty.
基金supported by the National Natural Science Foundation of China(52204332 and 52174290)the Outstanding Youth Fund of Anhui Province(2208085J19)the Natural Science Foundation of the Jiangsu Higher Education Institutions of China(21KJB450002).
文摘Developing deNO_(x)catalysts with lower activity temperatures range significantly reduces NH_(3)selective catalytic reduction(SCR)operating costs for low-temperature industrial flue gases.Herein,a novel FeVO_(4)/CeO_(2)catalyst with great low-temperature NH_(3)-SCR and nitrogen selectivity was synthesized using a dipping method.Characterization techniques such as X-ray diffraction,Raman spectroscopy,specific surface and porosity analysis,H2 temperature-programmed reduction,NH_(3)temperature-programmed desorption,X-ray photoelectron spectroscopy,and the in situ diffused reflectance infrared Fourier transform spectroscopy were used to investigate the catalytic mechanism.An appropriate addition for FeVO_(4)in the catalyst was 5 wt.%from the results,and the active substance content reached the maximum dispersal capacity of the carrier.The NO_(x)conversion exceeded 90%,and the nitrogen selectivity was more than 98%over this catalyst at 200–350℃.The activity was kept at 88%after 7.5 h of reaction at 200℃ for 7.5 h in 35 mg m^(-3)SO_(2)gas.The remarkable deNO_(x)activity,nitrogen selectivity,and sulphur resistance performances are attributed to the low redox temperature,the abundance of medium-strong acid and strong acid sites,the sufficient adsorbed oxygen,and the superior Fe^(2+)content on the surface.The Langmuir–Hinshelwood mechanism was observed on the FeVO_(4)/CeO_(2)catalyst in the NH_(3)selective catalytic reduction of NO_(x).
文摘Elemental doping of BiVO_(4) crystal lattices effectively enhances carrier separation,thereby facilitating efficient photoelectrochemical water splitting.However,the positive effect of elementally induced lattice distortions on hole extraction has been neglected.Herein,the crystal lattice of BiVO_(4) is distorted by doping with an inexpensive Cs metal;then,CoFe_(2)O_(4) is used as an efficient hole-extraction layer to further modify the surface of the doped photoanode.Benefiting from the above design,the newly prepared CoFe_(2)O_(4)-Cs-BiVO_(4) photoanode achieved a photocurrent density of 5.66 mA cm^(–2) at 1.23 V vs.a reversible hydrogen electrode,indicating a 3.9-fold improvement in photocurrent density.Detailed physicochemical characterization and density functional theory calculations showed that the lattice distortion induced by Cs doping promoted the directional migration of BiVO_(4) bulk-phase holes to the CoFe_(2)O_(4) layer.Additionally,the coupled CoFe_(2)O_(4) can be used as a hole extraction layer to further enhance the interfacial migration of carriers.The synergistic effect of the two effectively promotes the directional migration of photogenerated carriers from the BiVO_(4) bulk phase to the active sites of the oxygen evolution reaction,thereby effectively inhibiting carrier recombination.This study revealed the positive effect of the dual-hole extraction strategy on solar energy conversion,thereby opening new avenues for the rational design of photoanodes.
基金the National Key R&D Research Program of China(Grant No.2018YFB0905400)National Natural Science Foundation of China(Grant Nos.51622210,51872277,51802007,21606003,51972067,51802044,51672193,51420105002,51920105004,and U1910210)+3 种基金the Fundamental Research Funds for the Central Universities(WK2060140026)Guangdong Natural Science Funds for Distinguished Young Scholar(Grant No.2019B151502039)the DNL Cooperation Fund,CAS(DNL180310)Opening Project of CAS Key Laboratory of Materials for Energy Conversion.
文摘Given the advantages of being abundant in resources,environmental benign and highly safe,rechargeable zinc-ion batteries(ZIBs)enter the global spotlight for their potential utilization in large-scale energy storage.Despite their preliminary success,zinc-ion storage that is able to deliver capacity>400 mAh g^-1 remains a great challenge.Here,we demonstrate the viability of NH4V4O10(NVO)as high-capacity cathode that breaks through the bottleneck of ZIBs in limited capacity.The first-principles calculations reveal that layered NVO is a good host to provide fast Zn^2+ions diffusion channel along its[010]direction in the interlayer space.On the other hand,to further enhance Zn^2+ion intercalation kinetics and long-term cycling stability,a three-dimensional(3D)flower-like architecture that is self-assembled by NVO nanobelts(3D-NVO)is rationally designed and fabricated through a microwave-assisted hydrothermal method.As a result,such 3D-NVO cathode possesses high capacity(485 mAh g^-1)and superior long-term cycling performance(3000 times)at 10 A g^-1(~50 s to full discharge/charge).Additionally,based on the excellent 3D-NVO cathode,a quasi-solid-state ZIB with capacity of 378 mAh g^-1is developed.
基金financially supported by the National Natural Science Foundation of China(Nos.21663027,21808189)the Fundamental Research Funds for the Central Universities of Chang’an University(No.300102299304)the Natural Science Basic Research Fund of Shaanxi Province(No.2020JZ20)。
文摘Photoelectrochemical(PEC)technology is considered to be a promising approach for solar-driven hydrogen production with zero emissions.Bismuth vanadate(BiVO_(4))is a kind of photocatalytic material with strong photoactivity in the visible light region and appropriate band gap for PEC water splitting.However,the solar-to-hydrogen efficiency(STH)of BiVO_(4)is far away from the 10%target needed for practical application due to its poor charge separation ability.Therefore,this review attempts to summarize the strategies for improving the photocurrent density and especially hydrogen production of BiVO_(4)materials through PEC techniques in the last three years,such as doping nonmetal and metal elements,depositing noble metals,constructing heterojunctions,coupling with carbon and metalorganic framework(MOF)materials to further enhance the PEC performance of BiVO_(4)photoanode.This review aims to serve as a general guideline to fabricate highly efficient BiVO_(4)-based materials for PEC water splitting.
基金Universiti Brunei Darussalam through grant numbers UBD/RSCH/1.4/FICBF(b)/2018/009 and UBD/PNC2/2/RG/1(313).
文摘We report a photoelectrochemical investigation of BiVO4 photoanodes prepared by successive ionic layer adsorption and reaction(SILAR),a facile method that yields uniform nanoporous films.After characterization of the phase,morphology,composition,and optical properties of the prepared films,the efficiencies of charge separation(ηsep)and water oxidation(ηox)in solar water splitting cells employing these photoanodes were estimated following a previously reported procedure.Unexpected wavelength and illumination direction dependencies were discovered in the derived efficiencies,casting doubt on the validity of the analysis.An alternative approach using a diffusion–reaction model that explicitly considers the efficiency of electron collection resolved the discrepancies and explained the illumination direction dependence of the photocurrent.Electron diffusion lengths(Ln)of 0.45μm and 0.55μm were derived for pristine and cobalt phosphate(Co-Pi)modified BiVO4,respectively,which are much shorter than the film thickness of^2.1μm.The Co-Pi treatment also increasedηoxfrom 0.86 to^1,which is the main reason for the overall performance enhancement caused by adding Co-Pi.These findings suggest that there is little scope for improving the performance of SILAR-deposited BiVO4 photoanodes by further catalyzing water oxidation,but enhanced performance is achievable if electron transport can be improved.
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.
基金supported by the Khalifa University of Science and Technology under the Advanced Materials Chemistry Center(AMCC).
文摘As global energy demand continues to rise with fossil fuels dwindling at a faster rate,posing energy and environmental concerns,there is a growing interest in exploring alternative,green,and renewable energy sources.Ammonia is a key hydrogen energy carrier and precursor to many value-added products,and the efforts for its generation at commercial scale using greener methods are intensifying to mitigate the reliance on the energy-intensive Haber-Bosch process.The electrochemical nitrogen reduction reaction(e-NRR)is a highly promising way of synthesizing ammonia under energy-efficient,green,and ambient conditions.Despite its attractive potential,the activity and efficiency of conventional e-NRR catalysts are still a major concern due to low selectivity and poor ammonia yields.Inspired by the FeFe and FeV cofactors present in nitrogenases,this study reports the synthesis and electrocatalytic evaluation of FeVO_(4)catalyst for N_(2)reduction.The FeVO_(4)nanoparticles anchored on Fe foam(FF)could serve as an efficient electrocatalyst for the electrochemical nitrogen fixation,achieving a significant performance with highest NH_(3)yield of 22.5μg·h^(-1)·mg^(-1)and Faradaic efficiency(FE)of 20.74%at-0.2 VRHE in 0.1 M Na_(2)SO_(4).The FeVO_(4)electrocatalyst exhibited robust electrochemical stability for 24 h of operation at-0.2 VRHE.The high catalytic performance originated from the synergistic interactions between Fe and V which serve as dual electron donation centers for effective e-NRR.Furthermore,the coupling interaction between FeVO_(4)and FF support exposed abundant intrinsic active sites and facilitated beneficial charge transfer further inducing superior e-NRR activity.Density functional theory(DFT)computations disclosed that surface Fe atoms are the main active centers for e-NRR which proceed via the alternating pathway.
