A novel unique popcorn-like three-dimensional(3D)hierarchical structural electrocatalyst is synthesized by the pyrolysis of ZIF-8/ZIF-67 and polyacrylonitrile fiber composites,where popcorn-like Co_(3)O_(4) nanopartic...A novel unique popcorn-like three-dimensional(3D)hierarchical structural electrocatalyst is synthesized by the pyrolysis of ZIF-8/ZIF-67 and polyacrylonitrile fiber composites,where popcorn-like Co_(3)O_(4) nanoparticles coated with nitrogen-doped amorphous carbon anchor onto the tips of N-doped carbon nanotubes(NCNTs),and the NCNTs grow on carbon nanofiber(NAC@Co_(3)O_(4)/NCNTs/CNF).Owing to the positive synergistic effects of 3D hierarchical NCNT networks and popcorn-like Co_(3)O_(4) species,NAC@Co_(3)O_(4)/NCNTs/CNF shows a record outstanding hydrogen evolution reaction performance(HER;the overpotential at 10 mA cm^(-2) is just 76 mV)and wonderful stability for the oxygen reduction reaction(ORR;73%retention of initial ORR activity after 70 h).Density functional theory(DFT)calculations demonstrate that the chemical interaction between the popcorn-like Co_(3)O_(4) species and NCNTs benefit the chemisorption of hydrogen and oxygen-containing intermediates,thus accelerating the performance of ORR,OER,and HER.Furthermore,we assembled NAC@Co_(3)O_(4)/NCNTs/CNF as a rechargeable Zn-air battery and an overall water splitting device,displaying a maximum power density of 267.58 mW cm^(-2) and almost 100%faradaic efficiency,which provides a promising prospect for surpassing traditional trifunctional electrocatalysts.It is expected that this finding will offer a new concept for synthesizing highly efficient trifunctional materials and applications.展开更多
基金supported by the National Natural Science Foundation of China(NSFC)(Grants 51772073,51762013)the Key Project of Hebei Natural Science Foundation(E2020201030)+3 种基金the Beijing-Tianjin-Hebei Collaborative Innovation Community Construction Project(21344301D)the Second Batch of Young Talent of Hebei Province(No.70280016160250,No.70280011808)the Key Fund in Hebei Province Department of Education China(ZD2021014)the Central Government Guide Local Funding Projects for Scientific and Technological Development(216Z4404G).
文摘A novel unique popcorn-like three-dimensional(3D)hierarchical structural electrocatalyst is synthesized by the pyrolysis of ZIF-8/ZIF-67 and polyacrylonitrile fiber composites,where popcorn-like Co_(3)O_(4) nanoparticles coated with nitrogen-doped amorphous carbon anchor onto the tips of N-doped carbon nanotubes(NCNTs),and the NCNTs grow on carbon nanofiber(NAC@Co_(3)O_(4)/NCNTs/CNF).Owing to the positive synergistic effects of 3D hierarchical NCNT networks and popcorn-like Co_(3)O_(4) species,NAC@Co_(3)O_(4)/NCNTs/CNF shows a record outstanding hydrogen evolution reaction performance(HER;the overpotential at 10 mA cm^(-2) is just 76 mV)and wonderful stability for the oxygen reduction reaction(ORR;73%retention of initial ORR activity after 70 h).Density functional theory(DFT)calculations demonstrate that the chemical interaction between the popcorn-like Co_(3)O_(4) species and NCNTs benefit the chemisorption of hydrogen and oxygen-containing intermediates,thus accelerating the performance of ORR,OER,and HER.Furthermore,we assembled NAC@Co_(3)O_(4)/NCNTs/CNF as a rechargeable Zn-air battery and an overall water splitting device,displaying a maximum power density of 267.58 mW cm^(-2) and almost 100%faradaic efficiency,which provides a promising prospect for surpassing traditional trifunctional electrocatalysts.It is expected that this finding will offer a new concept for synthesizing highly efficient trifunctional materials and applications.
