Recent Advances in Biomimetic Electrocatalysts for Water Splitting: Emerging Trends and Outlook

Electrochemical water splitting offers a sustainable pathway for green hydrogen production; however, it remains constrained by the sluggish kinetics of the hydrogen evolution and oxygen evolution reactions. Nature's metalloenzymes, such as [FeFe] hydrogenases and the Mn 4 CaO 5 cluster in photosystem II, exemplify exceptional catalytic efficiency using earth‐abundant metals via proton‐coupled electron transfer and cooperative metal‐site interactions. This review highlights the advances in biomimetic electrocatalysts and traces their evolution from molecular analogs to heterogeneous systems, including oxygen‐evolving complex mimic Mn/Ca clusters, biomimetic metal–porphyrinoids, metal–organic and covalent frameworks, nanostructured layered double hydroxides, Janus chalcogenides, high‐entropy alloys, and single‐atom catalysts. Hierarchical, self‐healing, and dynamically stable architectures that sustain catalytic activity under operational stress are emphasized, supported by ultrafast operando spectroscopies that capture real‐time active‐site transformations. Emerging strategies, such as decoupled water splitting, direct seawater electrolysis, and the integration of machine learning and digital twin frameworks, are accelerating predictive catalyst design and system‐level optimization. Adapting bioinspired design principles into electrolyzer architectures further enhances system efficiency. Despite meaningful advances, biomimetic systems remain hampered by their constrained durability, synthetic scale‐up challenges, and unresolved mechanistic intricacies. Their progress toward practical electrolyzer technologies hinges on the concerted integration of bioinspired design, material innovation, and high‐fidelity characterization.