This study presents the successful synthesis of a novel Z-scheme heterojunction composite film consisting of Ag/Bi_(2)MoO_(6)/BiOBr through electrochemical processes and ionexchange techniques,followed by the photodep...This study presents the successful synthesis of a novel Z-scheme heterojunction composite film consisting of Ag/Bi_(2)MoO_(6)/BiOBr through electrochemical processes and ionexchange techniques,followed by the photodeposition of noble metal silver(Ag)onto the composite structure.The catalytic efficiency of semiconductor photocatalysts is greatly improved by utilizing the localized surface plasmon resonance(LSPR)effect observed in Ag nanoparticles(NPs).Furthermore,the noble metal Ag serves as an intermediary bridge facilitating charge transfer between Bi_(2)MoO_(6)and BiOBr,while the formation of a Schottky barrier effectively inhibits the recombination of photo-generated electron-hole pairs.As a result,the Ag-deposited Bi_(2)MoO_(6)/BiOBr film exhibits superior photocatalytic performance in the reduction of CO_(2)compared to its unmodified counterpart.Our experimental results indicate a non-linear relationship between Ag deposition and the efficiency of photocatalytic CO_(2)reduction to CO,characterized by an initial increase in efficiency followed by a decline.The optimized 1.5%-Ag/Bi_(2)MoO_(6)/BiOBr film demonstrates exceptional photocatalytic activity,attaining a CO production rate of 13.65μmol/(g·h).This research explores the fundamental mechanisms that lead to improved photocatalytic CO_(2)reduction capabilities of the Ag/Bi_(2)MoO_(6)/BiOBr film.Our research offers important perspectives for the thoughtful design and production of highly efficient photocatalysts,which are essential for advancing sustainable energy solutions.展开更多
Ethylene(C_(2)H_(4))in vehicle exhaust is a highly reactive volatile organic compound(VOC).Its photooxidative reaction with NOx contributes to the formation of O3 and secondary organic aerosols(SOA),the latter being a...Ethylene(C_(2)H_(4))in vehicle exhaust is a highly reactive volatile organic compound(VOC).Its photooxidative reaction with NOx contributes to the formation of O3 and secondary organic aerosols(SOA),the latter being a key precursor of PM_(2.5).In this study,a novel MgO-supported Ag-Cu bimetallic catalyst was designed and investigated using density functional theory(DFT).The effects of Ag and Cu loading on the geometric structure,stability,and reactant adsorption characteristics of the catalyst were analyzed,and the catalytic oxidation pathways of C_(2)H_(4)over AgCu-MgO was elucidated.The results indicate that loading Ag significantly enhances the adsorption of C_(2)H_(4).The incorporation of Cu into Ag-MgO to form a AgCu-MgO bimetallic catalyst(dual atom catalyst,DACS)further improves the oxidative activity toward C_(2)H_(4).Based on the binding energies of the Ag and Cu bimetallic sites and the adsorption energies of C_(2)H_(4)and O_(2),three representative configurations were selected for detailed reaction pathway analysis.Among them,Configuration 6 of AgCu-MgO exhibited the highest catalytic oxidation performance.This study provides new atomic-scale insights for the rational design of efficient catalysts targeting olefinic pollutants in automotive emissions and offers valuable guidance for advancing exhaust after-treatment technologies.展开更多
基金Supported by the National Natural Science Foundation of China(21978196)Natural Science Foundation of Shanxi Province(201801D211008,202403021211018)+1 种基金Shanxi Provincial Education Department(S202413597023)Jincheng High Efficiency Conversion and Utilization Technology Innovation Center of CO2 Energy and Biomass Energy。
文摘This study presents the successful synthesis of a novel Z-scheme heterojunction composite film consisting of Ag/Bi_(2)MoO_(6)/BiOBr through electrochemical processes and ionexchange techniques,followed by the photodeposition of noble metal silver(Ag)onto the composite structure.The catalytic efficiency of semiconductor photocatalysts is greatly improved by utilizing the localized surface plasmon resonance(LSPR)effect observed in Ag nanoparticles(NPs).Furthermore,the noble metal Ag serves as an intermediary bridge facilitating charge transfer between Bi_(2)MoO_(6)and BiOBr,while the formation of a Schottky barrier effectively inhibits the recombination of photo-generated electron-hole pairs.As a result,the Ag-deposited Bi_(2)MoO_(6)/BiOBr film exhibits superior photocatalytic performance in the reduction of CO_(2)compared to its unmodified counterpart.Our experimental results indicate a non-linear relationship between Ag deposition and the efficiency of photocatalytic CO_(2)reduction to CO,characterized by an initial increase in efficiency followed by a decline.The optimized 1.5%-Ag/Bi_(2)MoO_(6)/BiOBr film demonstrates exceptional photocatalytic activity,attaining a CO production rate of 13.65μmol/(g·h).This research explores the fundamental mechanisms that lead to improved photocatalytic CO_(2)reduction capabilities of the Ag/Bi_(2)MoO_(6)/BiOBr film.Our research offers important perspectives for the thoughtful design and production of highly efficient photocatalysts,which are essential for advancing sustainable energy solutions.
基金Supported by the National Natural Science Foundation of China Project(22362018)the Yunnan Fundamental Research Projects(202401AS070102)。
文摘Ethylene(C_(2)H_(4))in vehicle exhaust is a highly reactive volatile organic compound(VOC).Its photooxidative reaction with NOx contributes to the formation of O3 and secondary organic aerosols(SOA),the latter being a key precursor of PM_(2.5).In this study,a novel MgO-supported Ag-Cu bimetallic catalyst was designed and investigated using density functional theory(DFT).The effects of Ag and Cu loading on the geometric structure,stability,and reactant adsorption characteristics of the catalyst were analyzed,and the catalytic oxidation pathways of C_(2)H_(4)over AgCu-MgO was elucidated.The results indicate that loading Ag significantly enhances the adsorption of C_(2)H_(4).The incorporation of Cu into Ag-MgO to form a AgCu-MgO bimetallic catalyst(dual atom catalyst,DACS)further improves the oxidative activity toward C_(2)H_(4).Based on the binding energies of the Ag and Cu bimetallic sites and the adsorption energies of C_(2)H_(4)and O_(2),three representative configurations were selected for detailed reaction pathway analysis.Among them,Configuration 6 of AgCu-MgO exhibited the highest catalytic oxidation performance.This study provides new atomic-scale insights for the rational design of efficient catalysts targeting olefinic pollutants in automotive emissions and offers valuable guidance for advancing exhaust after-treatment technologies.
