In situ construction of porous hierarchical(Ni3-xFex)FeN/Ni heterojunctions toward efficient electrocatalytic oxygen evolution  

作　　者：Minglei Yan Kun Mao Peixin Cui Chi Chen Jie Zhao Xizhang Wang Lijun Yang Hui Yang Qiang Wu Zheng Hu 

机构地区：[1]Key Laboratory of Mesoscopic Chemistry of MOE and Jiangsu Provincial Laboratory of Nanotechnology,School of Chemistry and Chemical Engineering,Nanjing University,Nanjing 210023,China [2]Key Laboratory of Soil Environment and Pollution Remediation,Institute of Soil Science,Chinese Academy of Sciences,Nanjing 210008,China [3]Shanghai Advanced Research Institute,Chinese Academy of Sciences,Shanghai 201210,China

出　　处：《Nano Research》2020年第2期328-334,共7页纳米研究（英文版）

基　　金：This work was jointly supported by the National Key Research and Development Program of China(Nos.2017YFA0206500 and 2018YFA0209103);the National Natural Science Foundation of China(Nos.21832003,21773111,51571110,and 21573107);the Fundamental Research Funds for the Central Universities(No.020514380126).

摘　　要：As a choke point in water electrolysis,the oxygen evolution reaction(OER)suffers from the severe electrode polarization and large overpotential.Herein,the porous hierarchical hetero-(Nis Fe)FeN/Ni catalysts are in situ constructed for the eficient electrocatalytic OER.X-ray absorption fine structure characterizations reveal the strong Ni-Fe bimetallic interaction in(Niz Fex)FeN/Ni.Theoretical study indicates the heterojunction and bimetallic interaction decrease the free-energy change for the rate-limiting step of the OER and the overpotential thereof.In addition,the high conductivity and porous hierarchical morphology favor the electron transfer,electrolyte access and O2 release.Consequently,the optimized catalyst achieves a low overpotential of 223 mV at 10 mA.cm^-2,a small Tafel slope of 68 mV:dec^-1,and a high stability.The excellent performance of the optimized catalyst is also demonstrated by the overall water electrolysis with a low working voltage and high Faradaic efficiency.Moreover,the correlation between the structure and performance is well established by the experimental characterizations and theoretical calculations,which confirms the origin of the OER activity from the surface metal oxyhydroxide in situ generated upon applying the current.This study suggests a promising approach to the advanced OER electrocatalysts for practical applications by constructing the porous hierarchical metal-compound/metal heterojunctions.

关 键 词：oxygen evolution reaction electrocatalysts ternary Ni-Fe nitrides HETEROJUNCTIONS /n s/fty construction 

分 类 号：O64[理学—物理化学]