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.
