Recent advances and future prospects on Ni3S2-Based electrocatalysts for efficient alkaline water electrolysis

Green hydrogen (H2) produced by renewable energy powered alkaline water electrolysis is a promising alternative to fossil fuels due to its high energy density with zero-carbon emissions. However, efficient and economic H2 production by alkaline water electrolysis is hindered by the sluggish hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). Therefore, it is imperative to design and fabricate high-active and low-cost non-precious metal catalysts to improve the HER and OER performance, which affects the energy efficiency of alkaline water electrolysis. Ni3S2 with the heazlewoodite structure is a potential electrocatalyst with near-metal conductivity due to the Ni–Ni metal network. Here, the review comprehensively presents the recent progress of Ni3S2-based electrocatalysts for alkaline water electrocatalysis. Herein, the HER and OER mechanisms, performance evaluation criteria, preparation methods, and strategies for performance improvement of Ni3S2-based electrocatalysts are discussed. The challenges and perspectives are also analyzed.