Advances in Nickel‐Based Catalysts for Alkaline Water Electrolysis: Comprehensive Review of Current Research Direction for HER and OER Applications

Nickel-based catalysts are among the most promising materials for electrocatalytic water splitting, particularly for the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in alkaline media. Their abundance, cost-effectiveness, and tunable electrochemical properties make them attractive alternatives to precious metal catalysts. This review provides a comprehensive analysis of the advancements in nickel-based catalysts, including pure nickel, alloys, oxides, hydroxides, and spinels, emphasizing their synthesis methods, structural properties, and electrocatalytic performance. Recent nanostructuring, doping, and hybridization innovations with conductive supports have significantly enhanced catalytic activity, stability, and efficiency. Despite notable progress, challenges remain in improving long-term durability, minimizing surface degradation, and scaling up production for industrial applications. Addressing these limitations through advanced catalyst design, in situ characterization, and integration with renewable energy sources will be crucial for widely adopting nickel-based catalysts in sustainable hydrogen production. This review highlights the key developments and future directions in the field, underscoring the role of nickel-based materials in enabling the hydrogen economy and global decarbonization efforts.