Facile Synthesis of P-doped NiCo2S4 on Ni foam as an Efficient Electrocatalyst for Oxygen Evolution Reaction

초록

Water electrolysis includes two half-electrochemical reactions: the cathodic hydrogen evolution reaction (HER) and the anodic oxygen evolution reaction (OER) [1]. In this process, the OER is regarded as bottleneck because of the intrinsically sluggish kinetics, involving a multistep electron transfer process [2]. To address the issue, phosphosulfide materials have been extensively studied as effective electrocatalyst for OER [3,4]. However, practical application of these materials is limited by their complex synthesis method. In this work, P-doped NiCo2S4 nanoneedles directly grown on nickel foam (NF) were prepared by a simple one-step phosphosulfurization with P2S5 as both phosphorus and sulfur source. The as-synthesized P-doped NiCo2S4 on NF exhibited outstanding electrocatalytic performance for OER in alkaline media, with a low overpotential of 300 mV at a current density of 50 mA cm?2 and excellent long-term stability for 100 h. Such high electrocatalytic performance was mainly attributed to the unique morphology covered by nanoneedles, an optimal electronic structure of NiCo2S4 derived from the introduced P species, and the binder-free growth on NF. This research will provide a simple and efficient method for preparing heteroatom-doped transition metal-based sulfide materials via one-step phosphosulfurization for various energy conversion and storage applications.