Molten salt electrolysis synthesis of NbS₂@MoS₂ and its performance for water splitting into hydrogen

The hydrogen evolution reaction (HER) has broader research prospects than traditional hydrogen production methods, but because of its slow kinetics, low-cost and high-efficiency electrocatalysts have become parti-cularly important in HER. NbS₂@MoS₂ with the morphology of nanoflowers and nanosheets was prepared by one-step molten salt electrolysis. Using XRD, SEM, TEM, XPS, SAED and other methods to characterize the physical and chemical properties of the electrocatalysts. The results show that the NbS₂@MoS₂ nanoflower catalyst exhibits a polycrystalline state with a thin and film flower-like structure, and the Nb elements are uniformly distributed on the surface of MoS₂. The HER performance is verified by electrochemical tests. The test results show that the nanoflower structure shows excellent electrocatalytic performance in HER. In a 1 mol/L KOH solution, the overpotential is 292.9 mV at a current density of 10.0 mA·cm⁻², and the Tafel slope is 107.0 mV·dec⁻¹, the charge transfer impe-dance is 31.0 Ω, and the electrochemically active surface area is 13.7 mF·cm⁻². And after 20 h of catalysis, it can still maintain good electrocatalytic activity. Nb deposition forms defects on the surface of MoS₂, and at the same time forms NbS₂ on the surface, which provides more active sites and improves water splitting performance. High-temperature molten salt electrocrystallization provides a new method for the synthesis of catalytic materials.