Three-dimensional structured of V-doped CoP <i>in situ</i> grown on MXene as highly efficient bifunctional electrocatalyst for water splitting
Hong Wang, Huimin Jiang, Yongqi Niu, Nasir A. Siddiqui, Aslam Khan, Pan Lu, Jianjian Lin
Abstract
A challenging but very important task is the development of efficient and cost effective non-noble metal based bifunctional electrocatalysts with excellent kinetics for overall water splitting. Improving the catalyst's electronic structure, optimizing intermediate adsorption, and enhancing charge transfer kinetics are crucial for enhancing reaction efficiency. In this study, we prepared three-dimensional structured V-doped CoP grown in situ on MXene by one-step hydrothermal and controlled phosphorylation (defined as V-CoP/MXene@NF). The V doping not only optimises the electronic conductivity, but also creates a strong synergistic effect between the MXene and V-CoP components, enriching the active sites of the catalysts. The V-CoP/MXene@NF electrocatalyst can achieve a current density of 10 mA cm<sup>-2</sup> in 1.0 M KOH solution, with overpotentials of 78 mV and 223 mV for the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER), respectively. For overall water splitting, we used the catalyst as an anode and cathode assembly in an electrolytic cell, which could drive a current density of 10 mA cm<sup>-2</sup> with an overpotential of only 1.56 V and excellent durability. This work provides new ideas for designing novel MXene-based non-noble metal bifunctional electrocatalysts.