Deposition of Cu on Ni3S2 nanomembranes with simply spontaneous replacement reaction for enhanced hydrogen evolution reaction

The integration of metal with transition metal disulfides (TMDs) is considered as one of the promising strategies to improve the hydrogen evolution reaction (HER) performance of TMDs through modifying the electrocatalytic kinetics. However, the deposition of metal on TMDs often requires reducing agents, surfactants or extra energy consumption, which increases the synthesis complexity and application cost. Here, metallic Cu was deposited on the Ni3S2 nanomembranes in situ grown on nickel foam (Cu/Ni3S2/NF), which is achieved through a simple replacement reaction between Cu2+ and Ni at room temperature. The microstructure characterizations reveal that Cu was uniformly distributed on Ni3S2 nanomembranes in amorphism. The XPS measurements indicate that the decoration of Cu makes the enrichment and depletion of electrons in S and Ni, respectively. Electrochemical testing shows that Cu/Ni3S2/NF has superior electrocatalytic activity with low overpotential of 130 mV to deliver a current density of 10 mA cm(-2) for HER in 1.0 M KOH, and a Tafel slope of 84.19 mV dec(-1). Furthermore, Cu/Ni3S2/NF possesses excellent electrocatalytic stability with nearly no increase in overpotential after continuously catalyzing for 48 h at a current density of -50 mA cm(-2). This work paves the ways to prepare high-performance electrocatalysts based on metal modified TMDs with a simple and low-cost route, which is expected to promote the practical HER application of TMDs.

Automated summary

This study presents a simple and low-cost method to deposit metallic Cu on Ni3S2 nanomembranes, resulting in high-performance electrocatalysts. Microstructural and XPS characterizations reveal the uniform distribution of Cu on Ni3S2 and the modification of electron distributions in S and Ni. Electrochemical testing demonstrates the excellent electrocatalytic activity and stability of Cu/Ni3S2/NF, indicating its potential application in HER.