Regulation of Ni3S2@NiS Heterostructure Grown on Industrial Nickel Net for Improved Electrocatalytic Hydrogen Evolution

A novel all-in-one catalytic electrode containing a Ni3S2@NiS heterostructure (Ni3S2@NiS/Ni-Net) was in situ synthesized on an industrial nickel net (Ni-Net) using a one-step solvothermal method, in which ethanol was the solvent and thioacetamide was the sulfur source, respectively. The effects of the addition amount of the sulfur source on the composition, morphology, and electronic structure of the Ni3S2@NiS heterostructures and their electrocatalytic hydrogen evolution reaction (HER) activities were investigated. When 2 mmol of sulfur source was introduced, the prepared Ni3S2@NiS/Ni-Net electrode with a nanorod-like structure required overpotentials of 207 and 322 mV to drive the current densities of 100 and 500 mA/cm2, respectively, in 1 M KOH solution, and only needed the overpotential of 429 mV to deliver 1000 mA/cm2. Meanwhile, the Ni3S2@NiS/Ni-Net electrode can operate stably at a high current density of 90 mA/cm2 under harsh alkaline conditions for at least 100 h. The results show that the Ni3S2@NiS/Ni-Net electrode has high activity and stable HER performance at a high current density, which provides a new idea for the development of high-efficiency electrodes for industrial alkaline hydrogen production.