NiO/Co2P Nanosheets with Heterogeneous Structure as a Multifunctional Catalyst for Overall Water Splitting

Abstract

Exploring efficient and low-cost multifunctional electrocatalysts is a prerequisite for the development of energy storage and converting technology. In this work, NiO/Co2P nanosheets (NiO/Co2P NSs) with heterogeneous structure were investigated through hydrothermal method, annealing and phosphating processes. Considering the synergistic effect between NiO and Co2P, we demonstrated the excellent electrocatalytic properties of NiO/Co2P NSs for OER and HER. By optimizing the electronic structure of NiO and Co2P, as well as the high specific surface area of the nanosheet structure and the presence of a large number of mesopores, more active sites are exposed and the electrocatalytic efficiency is improved, thus providing excellent electrocatalytic performance. Specifically, NiO/Co2P NSs can reach 108 and 207 mV at the current density of 10 mA cm−2 in alkaline medium for HER and OER. And it requires a voltage of 1.57 V to reach a current density of 10 mA cm−2 for overall water splitting. In conclusion, this study demonstrates the critical contribution of heterogeneous structures to promote electrocatalytic properties and open new perspectives for designing multifunctional catalysts.