Doping Ni into CoB achieves surface reconstruction to promote efficient electrocatalytic hydrogen evolution reaction

Abstract

The effective advancement of skilled transition metal electrocatalysts is crucial for promoting the hydrogen evolution reaction (HER) in the process of water splitting. In this context, the integration of nickel (Ni) transition metal atoms into cobalt boride (CoB) is achieved through an electrochemical deposition approach, yielding a remarkably active electrocatalyst termed Ni@CoB for HER. At 10 mA cm−2, the HER overpotential is 63 mV with a Tafel slope of 64.73 mV dec-1. After 50 h of stability testing, there was no significant current decay observed. By employing material characterization techniques and DFT calculations, it has been shown that the incorporation of Ni leads to a surface reconstruction of CoB, thereby decreasing surface aggregation. The catalyst exhibits a uniform spherical porous structure, facilitating enhanced electron transfer. The doped Ni atoms form a bimetallic synergistic effect with Co atoms, not only increasing the stability of interatomic covalent bonds but also enhancing reaction kinetics. This study illuminates the influence of incorporating transition metal atoms into CoB on the activity of HER, presenting a promising strategy for designing high-performance catalysts for alkaline hydrogen evolution.