Ingenious establishment of transition metal-nitrogen-carbon electrocatalysts with diverse catalytic active sites and hierarchically porous frameworks is highly significant to boost the oxygen reduction reaction(ORR)in...Ingenious establishment of transition metal-nitrogen-carbon electrocatalysts with diverse catalytic active sites and hierarchically porous frameworks is highly significant to boost the oxygen reduction reaction(ORR)in Zn-air batteries(ZABs).In this study,Fe/Co co-doped zeolitic imidazolium frameworks(ZIFs)and graphitic carbon nitride(g-C_(3)N_(4))were integrated and pyrolyzed to construct carbon-based electrocatalysts containing Fe,Co and N elements(labelled as Co-CoFe@NRPC),in which atomic-sc ale FeN_x and CoN_x,and nano scale metallic Co and CoFe alloy moieties were aligned with hierarchically porous N-doped carbon frameworks constructed by interconnected micropolyhedrons,nano tubes and nanosheets.The diverse active moieties guaranteed excellent intrinsic catalytic activity,while the hierarchically porous N-doped carbon frameworks ensured admirable accessibility of the catalytic active sites,excellent electrical conductivity,satisfactory mass transport and good durability.Expectedly,the optimized Co-CoFe@NRPC-90(with 90 mg g-C_(3)N_(4) added)electrocatalyst exhibited excellent ORR performance with a high half-wave potential of 885 mV(vs.reversible hydrogen electrode(RHE)),diffusion-limiting current density of 6.15 mA·cm^(-2),desirable durability and methanol tolerance.Simultaneously,the liquid ZAB established with Co-CoFe@NRPC-90 as an air-cathode electrocatalyst manifested an outstanding power density(281 mW·cm^(-2))and specific capacity(820.9 mAh·g_(Zn)^(-1)),transcending the liquid ZAB based on a commercial Pt/C electrocatalyst.展开更多
基金the National Natural Science Foundation of China，the Open Project of State Key Laboratory Cultivation Base for Nonmetal Composites and Functional Materials
基金financially supported by the National Natural Science Foundation of China (No.51972109)the Natural Science Foundation of Hunan Province (No.2023JJ30276)+1 种基金the Scientific Research Fund of Hunan Provincial EducationDepartment,China (Nos.22A0473 and 20A225)the Postgraduate Research Innovation Fund of Hunan Institute of Science and Technology (No.2022-38)。
文摘Ingenious establishment of transition metal-nitrogen-carbon electrocatalysts with diverse catalytic active sites and hierarchically porous frameworks is highly significant to boost the oxygen reduction reaction(ORR)in Zn-air batteries(ZABs).In this study,Fe/Co co-doped zeolitic imidazolium frameworks(ZIFs)and graphitic carbon nitride(g-C_(3)N_(4))were integrated and pyrolyzed to construct carbon-based electrocatalysts containing Fe,Co and N elements(labelled as Co-CoFe@NRPC),in which atomic-sc ale FeN_x and CoN_x,and nano scale metallic Co and CoFe alloy moieties were aligned with hierarchically porous N-doped carbon frameworks constructed by interconnected micropolyhedrons,nano tubes and nanosheets.The diverse active moieties guaranteed excellent intrinsic catalytic activity,while the hierarchically porous N-doped carbon frameworks ensured admirable accessibility of the catalytic active sites,excellent electrical conductivity,satisfactory mass transport and good durability.Expectedly,the optimized Co-CoFe@NRPC-90(with 90 mg g-C_(3)N_(4) added)electrocatalyst exhibited excellent ORR performance with a high half-wave potential of 885 mV(vs.reversible hydrogen electrode(RHE)),diffusion-limiting current density of 6.15 mA·cm^(-2),desirable durability and methanol tolerance.Simultaneously,the liquid ZAB established with Co-CoFe@NRPC-90 as an air-cathode electrocatalyst manifested an outstanding power density(281 mW·cm^(-2))and specific capacity(820.9 mAh·g_(Zn)^(-1)),transcending the liquid ZAB based on a commercial Pt/C electrocatalyst.
