Surface reconstruction, doping and vacancy engineering to improve the overall water splitting of CoP nanoarrays
Yongkai Sun, Wenyuan Sun, Lihong Chen, Alan Meng, Guicun Li, Lei Wang, Jianfeng Huang, Aili Song, Zhenhui Zhang, Zhenjiang Li
Abstract
Development of a general regulatory strategy for efficient overall water splitting remains a challenging task. Herein, a simple, cost-fairness, and general fluorination strategy is developed to realize surface reconstruction, heteroatom doping, and vacancies engineering over cobalt phosphide (CoP) for acquiring high-performance bifunctional electrocatalysts. Specifically, the surface of CoP nanoarrays (NAs) becomes rougher, meanwhile F doped into CoP lattice and creating amounts of P vacancies by fluorination, which caused the increase of active sites and regulation of charge distribution, resulting the excellent electrocatalyst performance of F-CoP NAs/copper foam (CF). The optimized F-CoP NAs/CF delivers a lower overpotential of only 35 mV at 10 mA·cm−2 for hydrogen evolution reaction (HER) and 231 mV at 50 mA·cm−2 for oxygen evolution reaction (OER), and the corresponding overall water splitting requires only 1.48 V cell voltage at 10 mA·cm−2, which are superior to the most state-of-the-art reported electrocatalysts. This work provides an innovative and feasible strategy to construct efficient electrocatalysts.