Multidimensional Engineering Strategies for Transition Metal Selenide Electrocatalysts in Water Electrolysis with Performance Optimization Mechanisms and Future Perspectives

Hydrogen energy, as a carbon‐neutral, high‐energy‐density renewable clean energy source, is recognized as an ideal alternative to fossil fuels. Although water electrolysis has emerged as a core technology for hydrogen production, its advancement remains constrained by the exorbitant cost, scarcity, and inadequate stability of precious metal catalysts. Transition metal selenides (TMSes) has emerged as promising electrocatalytic materials due to their combined advantages of low cost, tunable electronic structures, and intrinsic activity comparable to noble metals. This review focuses on multidimensional engineering strategies to systematically analyze the performance optimization mechanisms of TMSes in hydrogen evolution reaction and oxygen evolution reaction. Five key aspects are comprehensively discussed: conductive substrate engineering, interfacial synergy effects, crystal facet and morphology regulation, cation/anion doping strategies, and single‐atom catalyst construction. Research demonstrates that the synergistic effects of multidimensional strategies can overcome the intrinsic limitations of TMSes, including restricted conductivity, active site passivation, and stability deficiencies. This establishes a theoretical framework for designing efficient‐stable‐low‐cost water electrolysis catalysts. Future studies should integrate in situ characterization with machine learning‐assisted computations to unveil the dynamic reaction interfaces and structural evolution patterns.