Abstract
Heterogeneous interfaces produced by inter-domain interactions on a nanoscale performs a crucial role in boosting the properties of an electrocatalyst toward oxygen evolution reaction(OER)process.Herein,a series of dual-phase electrodes with intimately connected heterointerfaces are prepared by in situ decomposing solid solution oxide of NixCoyFe100-x-yO,which grew on Ni foam massively via an ultrafast combustion approach.Particularly,with high-reaction kinetics caused by the reduction treatment at 450 ℃,the less electronegative Fe and Co are more oxyphilic than Ni,which facilitated their co-exsolution and formation of CoFe2O4/NiO oxide with enriched oxygen vacancies.Benefiting from the nanopor-ous framework,heterojunction structure,and oxygen defects,the self-supporting electrodes present rapid char-ge/mass transmission and provide abundant active sites for OER.The optimized sample(R-SNCF4.5)shows low overpotentials of 226 and 324 mV at 10 and 100 mA·cm-2,a small Tafel slope(46.7 mV·dec-1),and excellent stability.The assembled R-SNCF4.5//Pt/C/NF electrolyzer demonstrates continuous electrolysis over 50 h at a current density of 10 mA·cm-2,under 1.51 V.Density functional theory(DFT)calculations verify that the strong electronic modulation plays a critical part in the CoFe2O4/NiO hybrid by lowering the energy barriers for the rate-determining steps,and Fe sites are the most active OER sites.
基金项目
National Natural Science Foundation of China(52101251)
Natural Science Foundation of Hebei Province(E2020208069)
Natural Science Foundation of Hebei Province(B2020208083)
NETL
NSTL
万方数据