The edge-graphitized carbon nitride(C_(3)N_(4)-C g)was prepared by secondary pyrolysis to construct ZnO/C_(3)N_(4)-C g(ZCN)type-Ⅱheterojunction photocatalyst via a facile sonication dispersion method,which achieved∼...The edge-graphitized carbon nitride(C_(3)N_(4)-C g)was prepared by secondary pyrolysis to construct ZnO/C_(3)N_(4)-C g(ZCN)type-Ⅱheterojunction photocatalyst via a facile sonication dispersion method,which achieved∼7.04-fold and∼18.3-fold enhanced visible-light-driven photocatalytic performance for refrac-tory micropollutant removal and simultaneous hydrogen(H_(2))evolution respectively compared to con-ventional ZnO/g-C_(3)N_(4)Step-scheme heterojunction.The apparent quantum efficiency of the ZCN_(0.4)het-erojunction reaches 0.92%(λ=420 nm).Such excellent performance stems from that the edge-graphene moieties stitched onto the interface of heterojunction extend light absorption to the full visible spec-trum,meanwhile,the built-in electric field generated during Fermi level alignment accompanying fa-vorable band-bending structure provides an effective pathway for the rapid migration of photoinduced electrons via the edge graphene channel to improve interfacial charge separation efficiency.Interestingly,the midgap states introduced in ZCN heterojunction could temporarily retain photoexcited electrons to effectively inhibit the in situ carrier recombination for improved photocatalytic H_(2)evolution.Moreover,ZCN/peroxymonosulfate system exhibited excellent anti-interference performance against complex water bodies under visible illumination due to the synergistic effect between the co-existing anions and organic matter.Meanwhile,the eco-friendly nature of the ZCN/peroxymonosulfate system showed no biotoxicity of reaction filtrate on cell proliferation after treatment,which avoided secondary contamination.Consid-ering the outstanding performance in photocatalysis,the ZCN system exhibits broad potential for practical applications in water pollution control and green energy production.展开更多
Li-O_(2) batteries with extremely high specific energy density have been regarded as a kind of promising successor to current Li-ion batteries.However,the high charge overpotential for the decomposition of Li_(2)O_(2)...Li-O_(2) batteries with extremely high specific energy density have been regarded as a kind of promising successor to current Li-ion batteries.However,the high charge overpotential for the decomposition of Li_(2)O_(2) discharge product reduces the energy efficiency and triggers a series of side reactions that cause the Li-O_(2) batteries to have a limited lifetime.Herein,Co-doped C_(3)N_(4)(Co-C_(3)N_(4))photocatalysts were designed by an in situ thermal evaporation method to take advantage of the photo-assisted charging technology to conquer the shortcomings of Li-O_(2) batteries encountered in the charge process.Different from the commonly used photocatalysts,the Co-C_(3)N_(4) photocatalysts perform well no matter with and without illumination,owing to the Co doping induced conductivity and electrocatalytic ability enhancement.This makes the Co-C_(3)N_(4) reduce the charge and discharge overpotentials and improve the cycling performance of Li-O_(2) batteries(from 20 to 106 cycles)without illumination.While introducing illumination,the performance can be further improved:Charge voltage reduces to 3.3 V,and the energy efficiency increases to 84.84%,indicating that the Co-C_(3)N_(4) could behave as a suitable photocathode for Li-O_(2) batteries.Besides,the low charge voltage and the continuous illumination together weaken the corrosion of the Li anode,making the long-term high-efficiency operation of Li-O_(2) batteries no longer just extravagant hope.展开更多
基金supported by the Natural Science Foundation of Shenzhen(No.GXWD20201230155427003-20200802110025006)the National Natural Science Foundation of China(Nos.52170157 and 52111530188)+3 种基金the Major Program of Jiangxi Provincial Depart-ment of Science and Technology(No.2022KSG01004)the Natural Science Foundation of Shenzhen(No.JCYJ20220531095408020)the Start-up Grant Harbin Institute of Technology(Shenzhen)(No.IA45001007)the Start-up Talent Grant at Harbin Institute of Technology(Shenzhen)(No.HA11409066).
文摘The edge-graphitized carbon nitride(C_(3)N_(4)-C g)was prepared by secondary pyrolysis to construct ZnO/C_(3)N_(4)-C g(ZCN)type-Ⅱheterojunction photocatalyst via a facile sonication dispersion method,which achieved∼7.04-fold and∼18.3-fold enhanced visible-light-driven photocatalytic performance for refrac-tory micropollutant removal and simultaneous hydrogen(H_(2))evolution respectively compared to con-ventional ZnO/g-C_(3)N_(4)Step-scheme heterojunction.The apparent quantum efficiency of the ZCN_(0.4)het-erojunction reaches 0.92%(λ=420 nm).Such excellent performance stems from that the edge-graphene moieties stitched onto the interface of heterojunction extend light absorption to the full visible spec-trum,meanwhile,the built-in electric field generated during Fermi level alignment accompanying fa-vorable band-bending structure provides an effective pathway for the rapid migration of photoinduced electrons via the edge graphene channel to improve interfacial charge separation efficiency.Interestingly,the midgap states introduced in ZCN heterojunction could temporarily retain photoexcited electrons to effectively inhibit the in situ carrier recombination for improved photocatalytic H_(2)evolution.Moreover,ZCN/peroxymonosulfate system exhibited excellent anti-interference performance against complex water bodies under visible illumination due to the synergistic effect between the co-existing anions and organic matter.Meanwhile,the eco-friendly nature of the ZCN/peroxymonosulfate system showed no biotoxicity of reaction filtrate on cell proliferation after treatment,which avoided secondary contamination.Consid-ering the outstanding performance in photocatalysis,the ZCN system exhibits broad potential for practical applications in water pollution control and green energy production.
基金the National Key Research and Development(R&D)Program of China(No.2017YFE0198100)the National Natural Science Foundation of China(No.21725103)+2 种基金Key Research Program of the Chinese Academy of Sciences(No.ZDRW-CN-2021-3)Youth Innovation Promotion Association of Chinese Academy of Sciences(No.2020230)Changchun Science and Technology Development Plan Funding Project(No.21ZY06).
文摘Li-O_(2) batteries with extremely high specific energy density have been regarded as a kind of promising successor to current Li-ion batteries.However,the high charge overpotential for the decomposition of Li_(2)O_(2) discharge product reduces the energy efficiency and triggers a series of side reactions that cause the Li-O_(2) batteries to have a limited lifetime.Herein,Co-doped C_(3)N_(4)(Co-C_(3)N_(4))photocatalysts were designed by an in situ thermal evaporation method to take advantage of the photo-assisted charging technology to conquer the shortcomings of Li-O_(2) batteries encountered in the charge process.Different from the commonly used photocatalysts,the Co-C_(3)N_(4) photocatalysts perform well no matter with and without illumination,owing to the Co doping induced conductivity and electrocatalytic ability enhancement.This makes the Co-C_(3)N_(4) reduce the charge and discharge overpotentials and improve the cycling performance of Li-O_(2) batteries(from 20 to 106 cycles)without illumination.While introducing illumination,the performance can be further improved:Charge voltage reduces to 3.3 V,and the energy efficiency increases to 84.84%,indicating that the Co-C_(3)N_(4) could behave as a suitable photocathode for Li-O_(2) batteries.Besides,the low charge voltage and the continuous illumination together weaken the corrosion of the Li anode,making the long-term high-efficiency operation of Li-O_(2) batteries no longer just extravagant hope.
