Doping engineering is an effective strategy for graphitic carbon nitride(g-C_(3)N_(4))to improve its photocat-alytic hydrogen evolution reaction(HER)performance.In this work,a novel nitrogen and sulfur co-doped g-C_(3...Doping engineering is an effective strategy for graphitic carbon nitride(g-C_(3)N_(4))to improve its photocat-alytic hydrogen evolution reaction(HER)performance.In this work,a novel nitrogen and sulfur co-doped g-C_(3)N_(4)(N,S-g-C_(3)N_(4))is elaborately designed on the basis of theoretical predictions of first-principle density functional theory(DFT).The calculated Gibbs free energy of adsorbed hydrogen(ΔGH∗)for N,S-g-C_(3)N_(4) at the N-doping active sites is extremely close to zero(0.01 eV).Inspired by the theoretical predictions,the N,S-g-C_(3)N_(4) is successfully fabricated through ammonia-rich pyrolysis synthesis strategy,in which ammonia is in-situ obtained by pyrolyzing melamine.Subsequent characterizations indicate that the N,S-g-C_(3)N_(4) possesses high specific surface area,outstanding light utilization,good hydrophilicity,and efficient carrier transfer efficiency.Consequently,the N,S-g-C_(3)N_(4) displays an extremely high H2 evolution rate of 8269.9μmol g−1 h−1,achieves an apparent quantum efficiency(AQE)of 3.24%,and also possesses outsatnding durability.Theoretical calculations further demonstrate that N and S dopants can not only introduce doping energy level to reduce the band gap,but also induce charge redistribution to facilitate hydrogen adsorption,thus promoting the photocatalytic HER process.Moreover,femtosecond transient absorption(fs-TA)spectroscopy further corroborates the efficient photogenerated carrier transport of N,S-g-C_(3)N_(4).This research highlights a promising and reliable strategy to achieve superior photocatalytic activity,and exhibits significant guidance for precise designing high-efficiency photocatalysts.展开更多
Photocatalytic H_(2)production from water splitting is a promising candidate for solving the increasing energy crisis and environmental issues.Herein we report a novel g-C_(3)N_(4)/Ag In_(x)S_(y)S-scheme heterojunctio...Photocatalytic H_(2)production from water splitting is a promising candidate for solving the increasing energy crisis and environmental issues.Herein we report a novel g-C_(3)N_(4)/Ag In_(x)S_(y)S-scheme heterojunction photocatalyst for water splitting into stoichiometric H_(2)and H_(2)O_(2)under visible light.The catalyst was prepared by depositing 3D bimetallic sulfide(Ag In_(x)S_(y))nanotubes onto 2D g-C_(3)N_(4)nanosheets.Owing to the special 3D-on-2D configuration,the photogenerated carriers could be rapidly transferred and effectively separated through the abundant interfacial heterostructures to avoid recombination,and therefore excellent performance for visible light-driven water splitting could be obtained,with a 24-h H_(2)evolution rate up to 237μmol g^(-1)h^(-1).Furthermore,suitable band alignment enables simultaneous H_(2)and H_(2)O_(2)production in a 1:1 stoichiometric ratio.H_(2)and H_(2)O_(2)were evolved on the conduction band of g-C_(3)N_(4)and on the valance band of Ag In_(x)S_(y),respectively.The novel 3D-on-2D configuration for heterojunction construction proposed in this work provided alternative research ideas toward photocatalytic reaction.展开更多
将工业偏钛酸浆料和尿素混合均匀后高温煅烧制备g-C3N4/TiO2光催化复合材料,对其结构进行了表征,以NO为目标物、波长430~470 nm的12 W LED灯为光源,用对NO的去除率评价复合材料的气相光催化活性.结果表明,所制样品为氮掺杂Ti O2与g-C3N4...将工业偏钛酸浆料和尿素混合均匀后高温煅烧制备g-C3N4/TiO2光催化复合材料,对其结构进行了表征,以NO为目标物、波长430~470 nm的12 W LED灯为光源,用对NO的去除率评价复合材料的气相光催化活性.结果表明,所制样品为氮掺杂Ti O2与g-C3N4/TiO2的复合物.复合材料的最佳制备条件为尿素与偏钛酸质量比2：1,450℃下煅烧1 h,该条件下样品产率最高,对NO的去除率达48.40%.展开更多
Nanosized rare earth solid superacid SO42/TiO2-Nd2O3 was prepared and was used as a catalyst for cyclohexand dehydration to form cyclohexene.The influence of various preparation parameters such as the concentration of...Nanosized rare earth solid superacid SO42/TiO2-Nd2O3 was prepared and was used as a catalyst for cyclohexand dehydration to form cyclohexene.The influence of various preparation parameters such as the concentration of Nd3+,the concentration of H2SO4 and the calcination temperature on the catalytic activity was studied.It indicates that SO42-/TiO2-Nd2O3 has fairly high catalytic activity on the dehydration of cyclohexand and the yield of cyclohexene can reach 79.73%.The SO42-/TiO2-Nd2O3 catalytic mechanism for cyclohexand dehydration and the Nd3+ effect on the catalytic activity was also disccused.展开更多
基金supported by the National Natural Science Foun-dation of China(No.62004143)the Key R&D Program of Hubei Province(No.2022BAA084)the Natural Science Foundation of Hubei Province(No.2021CFB133).
文摘Doping engineering is an effective strategy for graphitic carbon nitride(g-C_(3)N_(4))to improve its photocat-alytic hydrogen evolution reaction(HER)performance.In this work,a novel nitrogen and sulfur co-doped g-C_(3)N_(4)(N,S-g-C_(3)N_(4))is elaborately designed on the basis of theoretical predictions of first-principle density functional theory(DFT).The calculated Gibbs free energy of adsorbed hydrogen(ΔGH∗)for N,S-g-C_(3)N_(4) at the N-doping active sites is extremely close to zero(0.01 eV).Inspired by the theoretical predictions,the N,S-g-C_(3)N_(4) is successfully fabricated through ammonia-rich pyrolysis synthesis strategy,in which ammonia is in-situ obtained by pyrolyzing melamine.Subsequent characterizations indicate that the N,S-g-C_(3)N_(4) possesses high specific surface area,outstanding light utilization,good hydrophilicity,and efficient carrier transfer efficiency.Consequently,the N,S-g-C_(3)N_(4) displays an extremely high H2 evolution rate of 8269.9μmol g−1 h−1,achieves an apparent quantum efficiency(AQE)of 3.24%,and also possesses outsatnding durability.Theoretical calculations further demonstrate that N and S dopants can not only introduce doping energy level to reduce the band gap,but also induce charge redistribution to facilitate hydrogen adsorption,thus promoting the photocatalytic HER process.Moreover,femtosecond transient absorption(fs-TA)spectroscopy further corroborates the efficient photogenerated carrier transport of N,S-g-C_(3)N_(4).This research highlights a promising and reliable strategy to achieve superior photocatalytic activity,and exhibits significant guidance for precise designing high-efficiency photocatalysts.
基金financially supported by the National Natural Science Foundation of China(Nos.52362012,42077162,51978323)Natural Science Foundation of Jiangxi Province(No.2022ACB203014)+4 种基金Major Discipline Academic and Technical Leaders Training Program of Jiangxi Province(Nos.20213BCJ22018,20232BCJ22048)Natural Science Project of the Educational Department in Jiangxi Province(No.GJJ2201121)Natural Science Foundation of Nanchang Hangkong University(No.EA202202256)Educational Reform Project of Jiangxi Province(No.JXYJG-2022-135)Nanchang Hangkong University Educational Reform Project(Nos.sz2214,sz2213,JY22017,KCPY1806)。
文摘Photocatalytic H_(2)production from water splitting is a promising candidate for solving the increasing energy crisis and environmental issues.Herein we report a novel g-C_(3)N_(4)/Ag In_(x)S_(y)S-scheme heterojunction photocatalyst for water splitting into stoichiometric H_(2)and H_(2)O_(2)under visible light.The catalyst was prepared by depositing 3D bimetallic sulfide(Ag In_(x)S_(y))nanotubes onto 2D g-C_(3)N_(4)nanosheets.Owing to the special 3D-on-2D configuration,the photogenerated carriers could be rapidly transferred and effectively separated through the abundant interfacial heterostructures to avoid recombination,and therefore excellent performance for visible light-driven water splitting could be obtained,with a 24-h H_(2)evolution rate up to 237μmol g^(-1)h^(-1).Furthermore,suitable band alignment enables simultaneous H_(2)and H_(2)O_(2)production in a 1:1 stoichiometric ratio.H_(2)and H_(2)O_(2)were evolved on the conduction band of g-C_(3)N_(4)and on the valance band of Ag In_(x)S_(y),respectively.The novel 3D-on-2D configuration for heterojunction construction proposed in this work provided alternative research ideas toward photocatalytic reaction.
文摘Nanosized rare earth solid superacid SO42/TiO2-Nd2O3 was prepared and was used as a catalyst for cyclohexand dehydration to form cyclohexene.The influence of various preparation parameters such as the concentration of Nd3+,the concentration of H2SO4 and the calcination temperature on the catalytic activity was studied.It indicates that SO42-/TiO2-Nd2O3 has fairly high catalytic activity on the dehydration of cyclohexand and the yield of cyclohexene can reach 79.73%.The SO42-/TiO2-Nd2O3 catalytic mechanism for cyclohexand dehydration and the Nd3+ effect on the catalytic activity was also disccused.
