Water electrolysis has been considered as a sustainable way for producing renewable energy of hydrogen.However,this process requires a low-cost and high-efficient hydrogen evolution reaction (HER) catalyst to improve the overall reaction efficiency.Molybdenum (Mo)-based electrocatalysts are regarded as the promising candidates to replace the benchmark but expensive Pt-based HER catalysts,due to their high activity and stability in a wide pH range.In this review,we present a comprehensive and critical summary on the recent progress in the Mo-based electrodes for HER,including molybdenum alloys,molybdenum sulfides,molybdenum selenides,molybdenum carbides,molybdenum phosphides,molybdenum borides,molybdenum nitrides,and molybdenum oxides.Particular attention is mainly focused on the synthetic methods of Mo-based materials,the strategies for increasing the catalytic activity,and the relationship between structure/composition and electrocatalytic performance.Finally,the future development and perspectives of Mo-based electrocatalysts toward high HER performance are proposed.