Preparation of Ni₃S₂ Electrocatalyst from Different Sulfur Sources and its Performance in Electrocatalytic Hydrogen Evolution Reaction

A series of Ni₃S₂ electrocatalysts were successfully prepared using nickel foam precursor as substrate and thiourea, sodium thiosulfate pentahydrate, sodium sulfide nonahydrate and sodium diethyldithiocarbamate as sulfur sources, and their performances in electrocatalytic hydrogen evolution (HER) were further compared. The results exhibited that the Ni₃S₂ catalyst prepared with sodium thiosulfate pentahydrate as the sulfur source showed the best performance in HER. At a current density of 10 mA cm⁻², the overpotential was only 178 mV, and the Tafel slope was 70.4 mV dec⁻¹. In addition, through the double-layer capacitance test, it was found that the catalyst had the highest electrochemical active area, and the capacitance reached 41.33 mF cm⁻², which was consistent with its excellent HER performance. In this work, the influence mechanism of different sulfur sources on the sulfurization process of Ni₃S₂ catalyst and the further impact of these effects on the performance of HER were also discussed in detail. These results provide a solid theoretical and experimental basis for optimizing the application of Ni₃S₂ catalyst in the field of electrocatalytic hydrogen production.