Synergistic effects of MoS2-decorated in situ NiFe nanoalloys/NiFe-LDH with superhydrophilicity for electrocatalytic overall water splitting

Abstract

In this work, NiFe-layered double hydroxide (NFL) nanosheet arrays loaded with NiFe nanoparticles (NiFe NPs) were prepared via a one-step partial reduction strategy and MoS₂/NiFe NPs/NFL/CC with sandwich structure was fabricated by integrating caterpillar-like few-layer MoS₂ nanosheets into NiFe NP interlayers over NFL nanosheets. Benefitting from the highly exposed active sites on MoS₂ layers, the crystal structure and excellent electronic properties of metal alloys as well as the optimized heterojunction structure, MoS₂/NiFe NPs/NFL/CC exhibited good electrocatalytic water splitting performance. The overpotentials for oxygen evolution reactions (OERs) and hydrogen evolution reactions (HERs) are 118 mV (η₁₀) and 212 mV (η₁₀), respectively, in 1.0 M KOH electrolyte. Due to the synergistic effects of interface engineering approaches, the overall water splitting device with MoS₂/NiFe NPs/NFL/CC as both electrodes exhibited a low voltage of 1.54 V at 10 mA cm⁻² and outstanding long-term stability for over 30 h. This interface engineering approach paves the way for the further investigation of NiFe-based electrocatalysts.