Superhydrophilic MoS2-Ni3S2 nanoflake heterostructures grown on 3D Ni foam as an efficient electrocatalyst for overall water splitting

Water splitting was considered to be a sustainable and promising strategy for production of clean hydrogen energy to address environmental crisis and potential energy. In this work, we present the cost-effective, convenient, and efficient method for in situ growth of peculiar MoS2-Ni3S2 nanoflake heterostructures on three-dimensional (3D) Ni foam. The synthesized electrocatalyst was used as a self-supported bifunctional electrode to catalyze oxygen evolution reaction (OER) and hydrogen evolution reaction (HER), and it exhibits an overpotential of 125 mV to achieve 10 mA cm(-2) for HER and an overpotential of 280 mV to achieve 40 mA cm(-2) for OER. In addition, the material presents a cell voltage of only 1.556 V (10 mA cm(-2)) for overall water splitting in 1 M KOH solution and a robust durability and long-term stability (over 50 h at 10 mA cm(-2)). The excellent electrocatalytic performance with superior stability is mainly due to the 3D porous conductive substrates, peculiar layered heterostructures, superhydrophilic surfaces, and synergistic advantages of bimetallic sulfides. The material has a great application prospect as an earth-abundant electrocatalyst in water splitting for large-scale hydrogen or oxygen production.