Facile Preparation Process of NiCoP–NiCoSe2 Nano-Bilayer Films for Oxygen Evolution Reaction with High Efficiency and Long Duration

Abstract

In order to explore a new electrocatalyst (or its precursor) for oxygen evolution reaction (OER), much attention has recently been given to the alternative engineering strategy for fabricating a novel nanofilm electrode with high efficiency and long duration. We herein use a two-step electrodeposition method to prepare a series of nanofilm electrodes containing Ni, Co, P, and Se on carbon cloth. After a suitable electrochemical activation process through cyclic voltammetry, the resultant binder-free NiCoP–NiCoSe₂ nano-bilayer films are transformed from compact layer(s) to porous nanoparticle ones composed by NiCo hydroxides and a small amount of NiCo oxyhydroxides and thus exhibit a striking electrocatalytic activity (lower to 243 mV overpotential for 10 mA cm–²) and excellent stability (80 h) for OER. The rougher surface, well-suited electronic structure originated from the Ni/Co codoping and the rational integration of NiCoP and NiCoSe₂ are important factors for the excellent OER performance of the NiCoP–NiCoSe₂ film after the electrochemical activation process. In addition, the results on overall water splitting reveal that the NiCoP–NiCoSe₂ film is also promising in the practical application of energy conversion and storage.