Ni(OH)-derived lamellar MoS/NiS/NF with Fe-doped heterojunction catalysts for efficient overall water splitting.

Heterostructures formed by combining semiconductor materials with different band structures can provide work functions, d-band positions and electronic properties different from bulk materials and are considered as an effective strategy to improve the catalytic activity through electronic modification. In this study, an efficient MoS/Fe-NiS/NF heterojunction material was prepared by a two-step hydrothermal method. With the help of flake Ni(OH) synthesized in the first step, growth sites were provided for flake NiS. The electronic structure of NiS was optimized by Fe doping, while the construction of the MoS/Fe-NiS heterostructure allowed the catalyst to expose more active sites. MoS/Fe-NiS/NF exhibited a small charge transfer resistance and excellent electrocatalytic performance. At a current density of 10 mA cm, only low overpotentials of 148 mV and 118 mV were required for the oxygen precipitation reaction (OER) and hydrogen precipitation reaction (HER), respectively. Notably, when MoS/Fe-NiS/NF is used as the anode and cathode for overall hydrolysis, only 1.51 V is required to reach a current density of 10 mA cm, demonstrating its great potential for application in hydrolysis. This work provides a feasible idea for the rational construction of non-precious metal bifunctional electrocatalysts with excellent performance.