Improving oxygen evolution reaction performance of Ni2P microflower via highly controlled defect engineering

초록

With the increasing concerns about the tremendous devastation of the environment and exhaustion of fossil fuel resources, the exploration of clean and sustainable energy has become an urgent issue all over the world. Hydrogen energy, which has superior gravimetric energy density and environmental benignity, is regarded as one of the renewable energy sources to replace the traditional fossil fuel.[1] Electrochemical water splitting is considered as an attractive eco-friendly technology for high-purity hydrogen production. Specifically, it is necessary to find cost-effective superior electrocatalysts for oxygen evolution reaction (OER) for developing efficiency of water splitting. Recently, bimetallic transition metal phosphides (TMPs) have been widely considered as promising electrocatalyst for OER in alkaline solution owing to their earth-abundance, easy synthetic procedure, and superior redox properties to monometallic one.[2] Additionally, the formation of phosphorus vacancies in TMPs can effectively enhance the electrical conductivity via regulating electronic band structure and reduce the energy barrier of the reaction intermediates during the four-electron reaction pathway of OER.[3] In this study, we synthesized phosphorus vacancy-rich Fe-doped Ni2P microflower using simple hydrothermal, phosphidation, and partial reduction procedure. The synergistic effect of the Fe doping and phosphorus vacancy and improved OER performance of the Fe-Ni2P-VP were investigated by physicochemical and electrochemical analysis. This work will offer new insights for preparation of defect-rich non-noble metal-based materials with enhanced electrocatalytic performance for upcoming energy storage and conversion system.