Monoclinic BiVO_(4) is a widely researched semiconductor in solar water splitting owing to its suitable characteristics. However, BiVO_(4) faces limitations, such as the inefficient separation and transportation of ph...Monoclinic BiVO_(4) is a widely researched semiconductor in solar water splitting owing to its suitable characteristics. However, BiVO_(4) faces limitations, such as the inefficient separation and transportation of photogenerated charges in the bulk and poor catalytic water oxidation reactions at the surface that affect the water-splitting efficiency. In this work, the Cs intercalation strategy at the surface of BiVO_(4) is proposed for the enhanced water splitting to H_(2) and O_(2) productions via the effective separation and transportation photogenerated charges and improved surface catalytic water oxidation reactions. The Cs ions are found to intercalate at the surface of BiVO_(4) and regulate the oxygen vacancies to provide active O_(2) production sites and stability. The surface intercalation of Cs boosts the photocurrent to 1.89 mA cm^(-2)at 1.23 V vs.reference hydrogen electrode(RHE). A stoichiometric evolution of H_(2) and O_(2) is recorded with a faradaic efficiency of 92%. The open-circuit voltage measurements confirmed the increase in the carrier lifetime with the work function tuning upon Cs intercalation. The proposed Cs intercalation strategy suggests an effective route to suppress the charge recombination with an increase in carrier lifetime and charge separation in BiVO_(4) for the enhanced PEC application.展开更多
A novel Z-scheme ZnFe_(2)O_(4)/BiVO_(4)heterojunction photocatalyst was successfully synthesized using a convenient solvothermal method and applied in the visible light photocatalytic degradation of ciprofloxacin,whic...A novel Z-scheme ZnFe_(2)O_(4)/BiVO_(4)heterojunction photocatalyst was successfully synthesized using a convenient solvothermal method and applied in the visible light photocatalytic degradation of ciprofloxacin,which is a typical antibiotic contaminant in wastewater.The heterostructure of as-synthesized catalysts was confirmed using X-ray diffraction,scanning electron microscopy,transmission electron microscopy and X-ray photoelectron spectroscopy characterizations.Compared with the singlephase counterparts,ZnFe_(2)O_(4)/BiVO_(4)demonstrated considerably enhanced photogenerated charge separation efficiencies because of the Z-scheme transfer mechanism of electrons between the composite photocatalysts.Consequently,the 30%ZnFe_(2)O_(4)/BiVO_(4)catalyst afforded a degradation rate of up to 97%of 20 mg/L ciprofloxacin under 30 min of visible light irradiation with a total organic carbon removal rate of 50%,which is an excellent activity compared with ever reported BiVO_(4)-based catalysts.In addition,the liquid chromatography-mass spectrometry and quantitative structure-activity relationships model analyses demonstrated that the toxicity of the intermediates was lower than that of the parent ciprofloxacin.Moreover,the as-synthesized ZnFe_(2)O_(4)/BiVO_(4)heterojunctions were quite stable and could be reused at least four times.This study thus provides a promising Z-scheme heterojunction photocatalyst for the efficient removal and detoxication of antibiotic pollutants from wastewater.展开更多
Regulating charge transfer to achieve specific transfer path can improve electron utilization and complete efficient photoreduction of CO_(2).Here,we fabricated a S-scheme heterojunction of CN/Fe-MOF by an in-situ ass...Regulating charge transfer to achieve specific transfer path can improve electron utilization and complete efficient photoreduction of CO_(2).Here,we fabricated a S-scheme heterojunction of CN/Fe-MOF by an in-situ assembly strategy.The S-scheme charge transfer mechanism was confirmed by band structure,electron spin resonance(ESR)and work function(Φ)analysis.On the one hand,the response of Fe-MOF in the visible region improved the utilization of light energy,thus increasing the ability of CN/Fe-MOF to generate charge carriers.On the other hand,CN,as the active site,not only had strong adsorption capacity for CO_(2),but also retained photogenerated electrons with high reduction capacity because of S-scheme charge transfer mechanism.Hence,in the absence of any sacrificial agent and cocatalyst,the optimized 50CN/Fe-MOF obtained the highest CO yield(19.17μmol g^(–1))under UV-Vis irradiation,which was almost 10 times higher than that of CN.In situ Fourier transform infrared spectra not only revealed that the photoreduction of CO_(2) occurred at the CN,but also demonstrated that the S-scheme charge transfer mechanism enabled 50CN/Fe-MOF to have a stronger ability to generate HCOO–than CN.展开更多
Exploring new and efficient photocatalysts to boost photocatalytic CO_(2) reduction is of critical importance for solar-to-fuel conversion.In this study,through the in-situ growth method,a series of S-scheme mechanism...Exploring new and efficient photocatalysts to boost photocatalytic CO_(2) reduction is of critical importance for solar-to-fuel conversion.In this study,through the in-situ growth method,a series of S-scheme mechanism Bi_(2)S_(3)/BiVO_(4)/Mn_(0.5)Cd_(0.5)S-DETA nanocomposites with good photocatalytic activity were synthesized.The extremely small size of Mn_(0.5)Cd_(0.5)S-DETA nanoparticles provides more active sites for photocatalytic reactions.In order to solve the serious shortcomings of sulfide photo-corrosion,BiVO_(4) were introduced as oxidation catalyst to consume too many holes and improve the stability of the material.In addition,the in-situ growth method produces the reduction cocatalyst Bi_(2)S_(3) during the BiVO_(4) and Mn_(0.5)Cd_(0.5)S-DETA recombination process,thereby improving the efficiency of charge transfer at their interface contact.The ternary composite unveils a higher CO_(2)-reduction rate(44.74μmol g^(−1) h^(−1))comparing with pristine BiVO_(4)(14.11μmol g^(−1) h^(−1)).The enhanced photocatalytic CO_(2) reduction performance is due to the special interface structure of the S-scheme Bi_(2)S_(3)/BiVO_(4)/Mn_(0.5)Cd_(0.5)S-DETA photocatalyst,which facilitates the charge separation at the interface and improves its photocatalytic activity and stability.展开更多
基金supported by the Basic Research&Development Program (2020R1F1A105408412)the C1 Gas Refinery Program(2015M3D3A1A0106489931) through the National Research Foundation of Korea (NRF) funded by the Ministry of Science and ICT,Republic of Korea。
文摘Monoclinic BiVO_(4) is a widely researched semiconductor in solar water splitting owing to its suitable characteristics. However, BiVO_(4) faces limitations, such as the inefficient separation and transportation of photogenerated charges in the bulk and poor catalytic water oxidation reactions at the surface that affect the water-splitting efficiency. In this work, the Cs intercalation strategy at the surface of BiVO_(4) is proposed for the enhanced water splitting to H_(2) and O_(2) productions via the effective separation and transportation photogenerated charges and improved surface catalytic water oxidation reactions. The Cs ions are found to intercalate at the surface of BiVO_(4) and regulate the oxygen vacancies to provide active O_(2) production sites and stability. The surface intercalation of Cs boosts the photocurrent to 1.89 mA cm^(-2)at 1.23 V vs.reference hydrogen electrode(RHE). A stoichiometric evolution of H_(2) and O_(2) is recorded with a faradaic efficiency of 92%. The open-circuit voltage measurements confirmed the increase in the carrier lifetime with the work function tuning upon Cs intercalation. The proposed Cs intercalation strategy suggests an effective route to suppress the charge recombination with an increase in carrier lifetime and charge separation in BiVO_(4) for the enhanced PEC application.
基金supported by the National Natural Science Foundation of China(22172064)the National Laboratory of Solid State Microstructures,Nanjing University(M34047)the financial support from the Qing Lan Project of Jiangsu Province。
基金the National Natural Science Foundation of China(Grant No.22172081)the National Key Research and Development Program of China(Grant No.2022YFC3901401)+1 种基金Special Funds for Science and Technology Innovation in Tianjin(Grant No.21ZXCCSN00010)the Fundamental Research Funds for the Central Universities.
文摘A novel Z-scheme ZnFe_(2)O_(4)/BiVO_(4)heterojunction photocatalyst was successfully synthesized using a convenient solvothermal method and applied in the visible light photocatalytic degradation of ciprofloxacin,which is a typical antibiotic contaminant in wastewater.The heterostructure of as-synthesized catalysts was confirmed using X-ray diffraction,scanning electron microscopy,transmission electron microscopy and X-ray photoelectron spectroscopy characterizations.Compared with the singlephase counterparts,ZnFe_(2)O_(4)/BiVO_(4)demonstrated considerably enhanced photogenerated charge separation efficiencies because of the Z-scheme transfer mechanism of electrons between the composite photocatalysts.Consequently,the 30%ZnFe_(2)O_(4)/BiVO_(4)catalyst afforded a degradation rate of up to 97%of 20 mg/L ciprofloxacin under 30 min of visible light irradiation with a total organic carbon removal rate of 50%,which is an excellent activity compared with ever reported BiVO_(4)-based catalysts.In addition,the liquid chromatography-mass spectrometry and quantitative structure-activity relationships model analyses demonstrated that the toxicity of the intermediates was lower than that of the parent ciprofloxacin.Moreover,the as-synthesized ZnFe_(2)O_(4)/BiVO_(4)heterojunctions were quite stable and could be reused at least four times.This study thus provides a promising Z-scheme heterojunction photocatalyst for the efficient removal and detoxication of antibiotic pollutants from wastewater.
文摘Regulating charge transfer to achieve specific transfer path can improve electron utilization and complete efficient photoreduction of CO_(2).Here,we fabricated a S-scheme heterojunction of CN/Fe-MOF by an in-situ assembly strategy.The S-scheme charge transfer mechanism was confirmed by band structure,electron spin resonance(ESR)and work function(Φ)analysis.On the one hand,the response of Fe-MOF in the visible region improved the utilization of light energy,thus increasing the ability of CN/Fe-MOF to generate charge carriers.On the other hand,CN,as the active site,not only had strong adsorption capacity for CO_(2),but also retained photogenerated electrons with high reduction capacity because of S-scheme charge transfer mechanism.Hence,in the absence of any sacrificial agent and cocatalyst,the optimized 50CN/Fe-MOF obtained the highest CO yield(19.17μmol g^(–1))under UV-Vis irradiation,which was almost 10 times higher than that of CN.In situ Fourier transform infrared spectra not only revealed that the photoreduction of CO_(2) occurred at the CN,but also demonstrated that the S-scheme charge transfer mechanism enabled 50CN/Fe-MOF to have a stronger ability to generate HCOO–than CN.
基金This work was supported by the National Natural Science Foundation of China(Nos.51572103 and 51973078)the Distinguished Young Scholar of Anhui Province(No.1808085J14)+1 种基金the Major projects of Education Department of Anhui Province(No.KJ2020ZD005)the Key Foundation of Educational Commission of Anhui Province(No.KJ2019A0595).
文摘Exploring new and efficient photocatalysts to boost photocatalytic CO_(2) reduction is of critical importance for solar-to-fuel conversion.In this study,through the in-situ growth method,a series of S-scheme mechanism Bi_(2)S_(3)/BiVO_(4)/Mn_(0.5)Cd_(0.5)S-DETA nanocomposites with good photocatalytic activity were synthesized.The extremely small size of Mn_(0.5)Cd_(0.5)S-DETA nanoparticles provides more active sites for photocatalytic reactions.In order to solve the serious shortcomings of sulfide photo-corrosion,BiVO_(4) were introduced as oxidation catalyst to consume too many holes and improve the stability of the material.In addition,the in-situ growth method produces the reduction cocatalyst Bi_(2)S_(3) during the BiVO_(4) and Mn_(0.5)Cd_(0.5)S-DETA recombination process,thereby improving the efficiency of charge transfer at their interface contact.The ternary composite unveils a higher CO_(2)-reduction rate(44.74μmol g^(−1) h^(−1))comparing with pristine BiVO_(4)(14.11μmol g^(−1) h^(−1)).The enhanced photocatalytic CO_(2) reduction performance is due to the special interface structure of the S-scheme Bi_(2)S_(3)/BiVO_(4)/Mn_(0.5)Cd_(0.5)S-DETA photocatalyst,which facilitates the charge separation at the interface and improves its photocatalytic activity and stability.
