Highly electrocatalytic and durable Co-Nx-C frameworks containing carbon nanofibers(CNFs)/carbon nitrides(CNs)are vital materials for rechargeable zinc-air batteries(RZABs).However,the existing Co-Nx-C frameworks expe...Highly electrocatalytic and durable Co-Nx-C frameworks containing carbon nanofibers(CNFs)/carbon nitrides(CNs)are vital materials for rechargeable zinc-air batteries(RZABs).However,the existing Co-Nx-C frameworks experience severe agglomeration during synthesis and limited active site accessibility/mechanical robustness.In this work,a photo-enhanced bifunctional catalyst with a type II p-n heterojunction(g-C_(3)N_(4)-Co@CNT/Co-N_(4)/C@CNF)is achieved through a combined“electrospinning+calcination+ball milling”approach.The composite integrates graphitic carbon nitride(g-C_(3)N_(4))nanosheets with dual active Co sites(nanoparticles and Co-N_(4)single atoms)anchored on conductive carbon nanofibers.This architecture enables efficient charge separation,enhanced light absorption,and accelerated oxygen redox kinetics.DFT calculations reveal that g-C_(3)N_(4)modulates the electronic structure and lowers the reaction free-energy barriers,leading the d-band center closer to the Fermi level.Under light irradiation,the g-C_(3)N_(4)-Co@CNT/Co-N_(4)/C@CNF exhibits outstanding ORR/OER catalytic performance,with a small overpotential gap of 0.684 V(E_(1/2)=0.930 V,E_(j:10)=1.614 V).In practical application:1)light-enhanced liquid ZABs with g-C_(3)N_(4)-Co@CNT/Co-N_(4)/C@CNF photoactive catalysts manifest a peak power density of 310 mW cm^(-2)and a long cycle life exceeding 1100 h.2)Light-enhanced flexible ZABs also can reach a peak power density of 96 mW cm^(-2)and tolerate a wide range of bending angles(0°-180°-0°)during harsh operation.This work offers a new platform for designing efficient photo-electrocatalysts and advancing next-generation solar-electrochemical energy conversion systems.展开更多
基金supported by the National Key Research and Development Program of China(2022YFE0138900)National Natural Science Foundation of China(21972017)+2 种基金the Fundamental Research Funds for the Central Universities(2232022D-18,CUSF-DH-T-2023061)Shanghai Sailing Program(22YF1400700)the Chenguang Program of Shanghai Education Development Foundation and Shanghai Municipal Education Commission(22CGA37).
文摘Highly electrocatalytic and durable Co-Nx-C frameworks containing carbon nanofibers(CNFs)/carbon nitrides(CNs)are vital materials for rechargeable zinc-air batteries(RZABs).However,the existing Co-Nx-C frameworks experience severe agglomeration during synthesis and limited active site accessibility/mechanical robustness.In this work,a photo-enhanced bifunctional catalyst with a type II p-n heterojunction(g-C_(3)N_(4)-Co@CNT/Co-N_(4)/C@CNF)is achieved through a combined“electrospinning+calcination+ball milling”approach.The composite integrates graphitic carbon nitride(g-C_(3)N_(4))nanosheets with dual active Co sites(nanoparticles and Co-N_(4)single atoms)anchored on conductive carbon nanofibers.This architecture enables efficient charge separation,enhanced light absorption,and accelerated oxygen redox kinetics.DFT calculations reveal that g-C_(3)N_(4)modulates the electronic structure and lowers the reaction free-energy barriers,leading the d-band center closer to the Fermi level.Under light irradiation,the g-C_(3)N_(4)-Co@CNT/Co-N_(4)/C@CNF exhibits outstanding ORR/OER catalytic performance,with a small overpotential gap of 0.684 V(E_(1/2)=0.930 V,E_(j:10)=1.614 V).In practical application:1)light-enhanced liquid ZABs with g-C_(3)N_(4)-Co@CNT/Co-N_(4)/C@CNF photoactive catalysts manifest a peak power density of 310 mW cm^(-2)and a long cycle life exceeding 1100 h.2)Light-enhanced flexible ZABs also can reach a peak power density of 96 mW cm^(-2)and tolerate a wide range of bending angles(0°-180°-0°)during harsh operation.This work offers a new platform for designing efficient photo-electrocatalysts and advancing next-generation solar-electrochemical energy conversion systems.
