Boosting Electrocatalytic Oxygen Evolution over Ce−Co<sub>9</sub>S<sub>8</sub> Core–Shell Nanoneedle Arrays by Electronic and Architectural Dual Engineering
Kun Liu, Zhuoya Zhu, Mengqi Jiang, Liangcheng Li, Linfei Ding, Meng Li, Dongmei Sun, Gaixiu Yang, Gengtao Fu, Yawen Tang
Abstract
Abstract An dual electronic and architectural engineering strategy is a good way to rationally design earth‐abundant and highly efficient electrocatalysts of the oxygen evolution reaction (OER) for sustainable hydrogen‐based energy devices. Here, a Ce‐doped Co 9 S 8 core–shell nanoneedle array (Ce−Co 9 S 8 @CC) supported on a carbon cloth has been designed and developed to accelerate the sluggish kinetics of the OER. Profiting from valance alternative Ce doping, a fine core–shell structure and vertically aligned nanoneedle arrayed architecture, Ce−Co 9 S 8 @CC integrates modulated electronic structure, highly exposed active sites, and multidimensional mass diffusion channels; together, these afford a favorable catalyzed OER. Ce−Co 9 S 8 @CC exhibits remarkable performance in the OER in an alkaline medium, where the overpotential requires only 242 mV to deliver a current density of 10 mA cm −2 for the OER; this is 70 mV superior to that of Ce‐free Co 9 S 8 catalyst and other counterparts. Good stability and impressive selectivity (nearly 100 % Faradic efficiency) are also demonstrated. When integrated into a two‐electrode OER//HER electrolyzer, the as‐prepared Ce−Co 9 S 8 @CC displays a low operation potential of 1.54 V at 10 mA cm −2 and long‐term stability, thus demonstrating great potential for economical water electrolysis.