Type‐II‐heterojunction TiO2nanorod arrays(NAs)are achieved by a combination of reduced and pristine TiO2NAs through a simple electrochemical reduction.The heterojunction‐structured TiO2NAs exhibit an enhanced photo...Type‐II‐heterojunction TiO2nanorod arrays(NAs)are achieved by a combination of reduced and pristine TiO2NAs through a simple electrochemical reduction.The heterojunction‐structured TiO2NAs exhibit an enhanced photo‐efficiency,with respect to those of pristine TiO2NAs and completely reduced black TiO2.The improved efficiency can be attributed to a synergistic effect of two contributions of the partially reduced TiO2NAs.The light absorption is significantly increased,from theUV to the visible spectrum.Moreover,the type II structure leads to enhanced separation and transport of the electrons and charges.The proposed electrochemical approach could be applied to various semiconductors for a control of the band structure and improved photoelectrochemical performance.展开更多
The sensitive and selective monitoring of nitrogen dioxide(NO_(2))can have a significant impact on environmental monitoring and health protection.Unfortunately,commercial NO_(2)sensors largely suffer from poor detecti...The sensitive and selective monitoring of nitrogen dioxide(NO_(2))can have a significant impact on environmental monitoring and health protection.Unfortunately,commercial NO_(2)sensors largely suffer from poor detection sensitivity and high operating temperatures.In this study,we developed a sensitive roomtemperature NO_(2)sensor based on an n-n heterojunction comprised of a Cs_(2)AgInCl_(6)perovskite with chlorine vacancies(VCl)and TiO_(2)nanotube arrays(VCl-Cs_(2)AgInCl_(6)/TiO_(2)NTs).In this design,the large number of chlorine vacancies in the Cs_(2)AgInCl_(6)perovskite act as active sites for oxygen adsorption and the subsequent sensing reaction.Benefitting from the formation of the n-n type heterojunction and the onedimensional structure of the TiO_(2)nanotubes,the Fermi levels are aligned,thereby facilitating the efficient transport of charge carriers between the target gas and the sensing interface.The resulting VClCs_(2)Ag In Cl_(6)/TiO_(2)NTs demonstrate a high response of 7.26 toward 1 ppm of NO_(2)at room temperature,possess a detection limit as low as 20 ppb,and have outstanding performance stability.This work widens the application of perovskite materials and indicates their potential application in medical diagnostics,environmental monitoring,and smart sensing systems.展开更多
NH_(2)-MIL-125 and its derivatives are receivingmore attention in various aspects of photocatalytic reactions,especially in the photocatalytic hydrogen peroxide(H_(2)O_(2))production from water(H_(2)O)and oxygen(O_(2)...NH_(2)-MIL-125 and its derivatives are receivingmore attention in various aspects of photocatalytic reactions,especially in the photocatalytic hydrogen peroxide(H_(2)O_(2))production from water(H_(2)O)and oxygen(O_(2)),which is a promising and sustainable strategy.However,the generation of H_(2)O_(2) from NH_(2)-MIL-125 is far from satisfactory due to rapid photo-generated carriers recombination and poor surface electron transfer.In the work,the composite photocatalyst CQDs/TiO_(2)/NH_(2)-MIL-125(C/T/NM)was designed for the first time by one-step hydrothermal method.TiO_(2) was in situ converted from partial NH_(2)-MIL-125(NM)during the successful loaded of Carbon quantum dots(CQDs)by hydrothermal process.The results indicated the typeⅡheterojunction was successfully constructed between the NM and TiO_(2) interface,which could promote the transmission of photo-generated electrons.In addition,the successful loaded of CQDs could effectively transfer and stored the photo-generated electrons to the photocatalyst surface to participate in the reaction,and further avoiding the recombination of photo-generated carriers.The C/T/NM composite photocatalyst achieved a H_(2)O_(2) generation of 455μmol/L for 5 hours under visible light without oxygen bubbling,whichwas 7.1 times superior to that of NM.The H_(2)O_(2) generation rate reached 645.4μM/(g·h),which was in priority in the reported literature under the same conditions.Finally,based on the active species capture experiments,energy band structure analysis and the photoelectrochemicalmeasurements,a possiblemechanism for the efficientH_(2)O_(2) generation through C/T/NM had been proposed.This work provided new ideas for designing NH_(2)-MIL-125 based composite photocatalysts for the production of H_(2)O_(2).展开更多
Photocatalytic reduction of carbon dioxide into valuable chemicals is a sustainable and promising technology that alleviates the greenhouse effect and energy crisis.In this study,the Mn_(3)O_(4)/FeNbO_(4) type Ⅱ hete...Photocatalytic reduction of carbon dioxide into valuable chemicals is a sustainable and promising technology that alleviates the greenhouse effect and energy crisis.In this study,the Mn_(3)O_(4)/FeNbO_(4) type Ⅱ heterojunction photocatalyst with a core-satellite structure was synthesized by the facile soft chemical method.The formation of a nano-heterojunction is supposed to effectively improve light capture,charge transfer,and interfacial charge separation in the photochemical reaction.Meanwhile,the heterojunction has a good ability to capture and activate CO_(2).Our results show that the prepared Mn_(3)O_(4)/FeNbO_(4) photocatalyst exhibit obvious enhanced catalytic properties in the photocatalytic CO_(2) reduction reaction,where the CH_(4) yielding rate is 1.96 and 9.81 times those of FeNbO_(4) and Mn_(3)O_(4),respectively.The transient photovoltage test(TPV)shows that the low frequency electrons are crucial to the effective transfer of photogenerated electrons and holes in the Mn_(3)O_(4)/FeNbO_(4) nano heterojunctions.Analysis of in situ Fourier transform infrared spectroscopy(FTIR)verifies the effective CO_(2) adsorption on the Mn_(3)O_(4)/FeNbO_(4) surface and the high selectivity of CH_(4) products.These properties of the Mn_(3)O_(4)/FeNbO_(4) photocatalyst infer its broad prospects in the fields of carbon fixation and energy conservation.展开更多
In photocatalysis,both the photogenerated charge separation and transport and the induced light utilization greatly influence performance.In this work,highly ordered CdS@ZnO core-shell inverse opal(CdS@ZnO-csIO)nanoco...In photocatalysis,both the photogenerated charge separation and transport and the induced light utilization greatly influence performance.In this work,highly ordered CdS@ZnO core-shell inverse opal(CdS@ZnO-csIO)nanocomposites have been successfully designed as a model to couple the heterojunction system with the slow photon effect for photocatalytic H2 production.Theoretical calculations and experimentation provide direct evidence for the slow photon effect in the CdS@ZnO-csIO nanocomposites.The type II heterojunction is responsible for promoting the migration and separation of photogenerated charges,and the slow photon effect is in charge of enhancing light harvesting in the CdS@ZnO-csIO nanocomposites.This synergy of two functions gives rise to a significantly enhanced photocatalytic H2 production rate under simulated solar light for the CdS@ZnO-csIO nanocomposites.The highest H2 production rate reaches 48.7 mmol g^(−1)h^(−1)under simulated solar light with the benchmark performance for all reported CdS@ZnO composites.Our work provides proof-of-principle that coupling the heterojunction system with the slow photon effect can greatly enhance the photocatalytic activity of composite photocatalysts.展开更多
基金supported from the National Natural Science Foundation of China (21425309, 21761132002, 21703040)China Postdoctoral Science Foundation (2017M622051) the 111 Project~~
文摘Type‐II‐heterojunction TiO2nanorod arrays(NAs)are achieved by a combination of reduced and pristine TiO2NAs through a simple electrochemical reduction.The heterojunction‐structured TiO2NAs exhibit an enhanced photo‐efficiency,with respect to those of pristine TiO2NAs and completely reduced black TiO2.The improved efficiency can be attributed to a synergistic effect of two contributions of the partially reduced TiO2NAs.The light absorption is significantly increased,from theUV to the visible spectrum.Moreover,the type II structure leads to enhanced separation and transport of the electrons and charges.The proposed electrochemical approach could be applied to various semiconductors for a control of the band structure and improved photoelectrochemical performance.
基金supported by the National Natural Science Foundation of China(No.22374015)the Fundamental Research Funds for the Central Universities(N2424020)+1 种基金Liaoning Province Foundation for Distinguished Young Scholars(No.1727146584490,to Y.-Y.Song)Liaoning Binhai laboratory(No.LBLG-2024-02)。
文摘The sensitive and selective monitoring of nitrogen dioxide(NO_(2))can have a significant impact on environmental monitoring and health protection.Unfortunately,commercial NO_(2)sensors largely suffer from poor detection sensitivity and high operating temperatures.In this study,we developed a sensitive roomtemperature NO_(2)sensor based on an n-n heterojunction comprised of a Cs_(2)AgInCl_(6)perovskite with chlorine vacancies(VCl)and TiO_(2)nanotube arrays(VCl-Cs_(2)AgInCl_(6)/TiO_(2)NTs).In this design,the large number of chlorine vacancies in the Cs_(2)AgInCl_(6)perovskite act as active sites for oxygen adsorption and the subsequent sensing reaction.Benefitting from the formation of the n-n type heterojunction and the onedimensional structure of the TiO_(2)nanotubes,the Fermi levels are aligned,thereby facilitating the efficient transport of charge carriers between the target gas and the sensing interface.The resulting VClCs_(2)Ag In Cl_(6)/TiO_(2)NTs demonstrate a high response of 7.26 toward 1 ppm of NO_(2)at room temperature,possess a detection limit as low as 20 ppb,and have outstanding performance stability.This work widens the application of perovskite materials and indicates their potential application in medical diagnostics,environmental monitoring,and smart sensing systems.
基金supported by the National Natural Science Foundation of China(NSFC)(No.52100101)and the National Scholarship Fund.
文摘NH_(2)-MIL-125 and its derivatives are receivingmore attention in various aspects of photocatalytic reactions,especially in the photocatalytic hydrogen peroxide(H_(2)O_(2))production from water(H_(2)O)and oxygen(O_(2)),which is a promising and sustainable strategy.However,the generation of H_(2)O_(2) from NH_(2)-MIL-125 is far from satisfactory due to rapid photo-generated carriers recombination and poor surface electron transfer.In the work,the composite photocatalyst CQDs/TiO_(2)/NH_(2)-MIL-125(C/T/NM)was designed for the first time by one-step hydrothermal method.TiO_(2) was in situ converted from partial NH_(2)-MIL-125(NM)during the successful loaded of Carbon quantum dots(CQDs)by hydrothermal process.The results indicated the typeⅡheterojunction was successfully constructed between the NM and TiO_(2) interface,which could promote the transmission of photo-generated electrons.In addition,the successful loaded of CQDs could effectively transfer and stored the photo-generated electrons to the photocatalyst surface to participate in the reaction,and further avoiding the recombination of photo-generated carriers.The C/T/NM composite photocatalyst achieved a H_(2)O_(2) generation of 455μmol/L for 5 hours under visible light without oxygen bubbling,whichwas 7.1 times superior to that of NM.The H_(2)O_(2) generation rate reached 645.4μM/(g·h),which was in priority in the reported literature under the same conditions.Finally,based on the active species capture experiments,energy band structure analysis and the photoelectrochemicalmeasurements,a possiblemechanism for the efficientH_(2)O_(2) generation through C/T/NM had been proposed.This work provided new ideas for designing NH_(2)-MIL-125 based composite photocatalysts for the production of H_(2)O_(2).
基金supported by the National Natural Science Foundation of China(Nos.52072152 and 51802126)the Jiangsu University Jinshan Professor Fund,the Jiangsu SpeciallyAppointed Professor Fund(No.17TPJS-003)Open Fund from Guangxi Key Laboratory of Electrochemical Energy Materials.
文摘Photocatalytic reduction of carbon dioxide into valuable chemicals is a sustainable and promising technology that alleviates the greenhouse effect and energy crisis.In this study,the Mn_(3)O_(4)/FeNbO_(4) type Ⅱ heterojunction photocatalyst with a core-satellite structure was synthesized by the facile soft chemical method.The formation of a nano-heterojunction is supposed to effectively improve light capture,charge transfer,and interfacial charge separation in the photochemical reaction.Meanwhile,the heterojunction has a good ability to capture and activate CO_(2).Our results show that the prepared Mn_(3)O_(4)/FeNbO_(4) photocatalyst exhibit obvious enhanced catalytic properties in the photocatalytic CO_(2) reduction reaction,where the CH_(4) yielding rate is 1.96 and 9.81 times those of FeNbO_(4) and Mn_(3)O_(4),respectively.The transient photovoltage test(TPV)shows that the low frequency electrons are crucial to the effective transfer of photogenerated electrons and holes in the Mn_(3)O_(4)/FeNbO_(4) nano heterojunctions.Analysis of in situ Fourier transform infrared spectroscopy(FTIR)verifies the effective CO_(2) adsorption on the Mn_(3)O_(4)/FeNbO_(4) surface and the high selectivity of CH_(4) products.These properties of the Mn_(3)O_(4)/FeNbO_(4) photocatalyst infer its broad prospects in the fields of carbon fixation and energy conservation.
基金supported by the National Key R&D Program of China(grant nos.2016YFA0202602 and 2021YFE0115800)the National Natural Science Foundation of China(grant nos.U20A20122 and 52103285)+3 种基金the 111 National Project(grant no.B20002)the Natural Science Foundation of Hubei Province(grant no.2020CFB416)the Fundamental Research Funds for the Central Universities(grant no.WUT:2021III016GX)the Open Fund Project of the State Key Laboratory of Advanced Technology for Materials Synthesis and Processing(Wuhan University of Technology,2021-KF-1).Youth Innovation Research Fund project of State Key Laboratory of Advanced Technology for Materials Synthesis and Processing(Wuhan University of Technology).
文摘In photocatalysis,both the photogenerated charge separation and transport and the induced light utilization greatly influence performance.In this work,highly ordered CdS@ZnO core-shell inverse opal(CdS@ZnO-csIO)nanocomposites have been successfully designed as a model to couple the heterojunction system with the slow photon effect for photocatalytic H2 production.Theoretical calculations and experimentation provide direct evidence for the slow photon effect in the CdS@ZnO-csIO nanocomposites.The type II heterojunction is responsible for promoting the migration and separation of photogenerated charges,and the slow photon effect is in charge of enhancing light harvesting in the CdS@ZnO-csIO nanocomposites.This synergy of two functions gives rise to a significantly enhanced photocatalytic H2 production rate under simulated solar light for the CdS@ZnO-csIO nanocomposites.The highest H2 production rate reaches 48.7 mmol g^(−1)h^(−1)under simulated solar light with the benchmark performance for all reported CdS@ZnO composites.Our work provides proof-of-principle that coupling the heterojunction system with the slow photon effect can greatly enhance the photocatalytic activity of composite photocatalysts.
