摘要
The kinetic process of a slow oxygen evolution reaction (OER) always constrains the efficiency of overall water electrolysis for H2 production.In particular,nonprecious metal electrodes for the OER have difficulty in possessing excellent electrocatalytic activity and stability in pH-universal media simultaneously.In this work,urea is first used as a pore-forming agent and active C/N source to fabricate a nanoporous NiFeCoCN medium-entropy alloy (MEA) by high-temperature sintering based on the nanoscale Kirkendall effect.The NiFeCoCN MEA achieves an overpotential of 432 mV at a current density of 10 mA·cm^(-2) and a lower Tafel slope of 52.4 mV·dec^(-1) compared to the IrO_(2)/Ti electrode (58.6 mV·dec^(-1)) in a 0.5 mol/L H_(2)SO_(4) solution.In a 1 mol/L KOH solution,the NiFeCoCN MEA obtains an overpotential of 175 mV for 10 mA·cm^(-2) and a Tafel slope of 40.8 mV·dec^(-1),which is better than IrO_(2)/Ni foam.This work proves a novel strategy to design and prepare nanoporous MEA materials with desirable C/N species,which provides promising prospects for the industrial production of H2 energy.
基金
supported by the National Key R&D Program of China(2017YFA0208200)
the National Natural Science Foundation of China(51862026,22022505 and 21872069)
the Aeronautical Science Foundation of China(2017ZF56027)
the Natural Science Foundation of Jiangxi Province(20192ACBL21048)
the Key Research and Development Program of Jiangxi Province(20203BBE53069)
the Fundamental Research Funds for the Central Universities of China(020514380266,020514380272 and 020514380274)
the Scientific and Technological Innovation Special Fund for Carbon Peak and Carbon Neutrality of Jiangsu Province(BK20220008)
the Nanjing International Collaboration Research Program(202201007 and 2022sx00000955)
the 2021 Suzhou Gusu Leading Talent Program of Science and Technology Innovationand Entrepreneurship in Wujiang District(ZXL2021273).
