Affiliation:
1. State Key Laboratory for Powder Metallurgy Central South University Lushan South Street 932 Changsha 410083 China
2. Department of Applied Physics The Hong Kong Polytechnic University Kowloon Hong Kong China
Abstract
AbstractNi–Fe bimetallic electrocatalysts are expected to replace existing precious metal catalysts for water splitting and achieve industrial applications due to their high intrinsic activity and low cost. However, the mechanism by which Ni and Fe species synergistically enhance catalytic activity remains obscure, which still needs further in‐depth study. In this study, a highly active bi‐functional electrocatalyst of Ni2P/FeP heterostructures is constructed on Fe foam (Ni2P/FeP‐FF), clearly illustrating the effect of Ni on Fe species for oxygen evolution reaction (OER) and revealing the true catalytic active phase for hydrogen evolution reaction (HER). The Ni2P/FeP‐FF only needs overpotentials of 217 and 42 mV to reach 10 mA cm−2 for OER and HER, respectively, exhibiting superior bi‐functional activity for overall water splitting. The Ni can elevate the strength of FeO on Ni2P/FeP‐FF surface and promote the formation of high‐valence FeOOH phase during OER, thus enhancing OER performance. Based on first‐principles calculations and Raman characterizations, the Ni2P/Ni(OH)2 heterojunction evolved from Ni2P/FeP is identified as the real high active phase for HER. This study not only builds a near‐commercial bifunctional electrocatalyst for overall water splitting, but also provides a deep insight for synergistic catalytic mechanism of Ni and Fe species.
Funder
National Natural Science Foundation of China
Subject
Electrochemistry,Condensed Matter Physics,Biomaterials,Electronic, Optical and Magnetic Materials
Cited by
61 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献