In Situ Growth of MoS 2 -Modified Ni–Fe LDH on Hierarchical Porous Nickel Foam as an Efficient Bifunctional Electrolytic Catalyst for Water Splitting

Developing high-performance bifunctional electrocatalytic materials with abundant elements on the earth’s surface is the foundation of the large-scale hydrogen evolution via water electrolysis, but it is still facing great challenges. Herein, MoS2-modified NiFe-layered double hydroxide (NiFe LDH) catalysts with microflower-like structures are in situ deposited on a treated three-dimensional porous nickel foam by a two-step hydrothermal strategy. Due to the unique interface characteristics, the MoS2/NiFe LDH-layered heterostructure helps to accelerate the mass diffusion and transfer rate, reduce the energy barrier of the reaction, and increase the chemical adsorption of larger reactive species for both the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER). Moreover, the well-designed 3D interconnected pores of hierarchical porous nickel foam (HP-NF) further enhance the quality of mass transfer. As expected, the as-fabricated optimal MoS2/NiFe LDH@HP-NF electrodes demonstrate greatly enhanced electrocatalytic activities, with the Tafel rate of 45.8 mV dec–1 and 66.2 mV dec–1 for OER and HER in a 1.0 M KOH solution.