Construction of an advanced MoS2/MoO3/NiFe-LDH/NF heterostructure catalyst toward boosting efficient alkaline oxygen evolution reaction†

Developing cost-effective metal electrocatalysts with high catalytic activity for overall water splitting is still a major challenge. NiFe layered double hydroxides (NiFe-LDHs), known for their abundance of oxygen defects and adjustable electronic properties, have garnered significant interest due to their unique heterostructures. This study employed electrodeposition to grow NiFe-LDH directly on the surface of affordable nickel foam (NF). Following this, MoS₂ was anchored and grown on the NiFe-LDH surface using the same electrodeposition method. The synthesis was completed by treating with a low concentration of H₂O₂, resulting in a self-supporting heterostructured catalyst (MoS₂/MoO₃/NiFe-LDH/NF). This catalyst features a nanosheet array structure and exhibits remarkable electrocatalytic efficiency and consistency in performance. In the oxygen evolution reaction (OER), the MoS₂/MoO₃/NiFe-LDH/NF catalyst showed overpotentials of 255 mV and 267 mV at current densities of 50 and 100 mA cm⁻², respectively, with a Tafel slope of 19.46 mV dec⁻¹. The MoS₂/MoO₃/NiFe-LDH/NF catalyst's well-defined heterostructure allows for the tweaking of the electronic structure and the enhancement of synergistic effects, optimizing the adsorption and desorption of oxygen-containing intermediates. This provides numerous active sites and improves capabilities in charge transfer. This research offers a new approach for designing NiFe-LDH heterostructured electrocatalysts with superior performance and low cost.