Direct Laser Writing of Bioinspired High‐Entropy Oxide Nanoarrays for Practical Water Electrolysis

Abstract Industrial water electrolysis faces a triple challenge at high current densities (≥500 mA cm −2 ): reconciling catalytic activity, stability, and severe gas‐liquid transport. While high‐entropy oxides (HEOs) show catalytic promise, conventional methods predominantly focus on elemental regulation and neglect critical morphological optimization, thus failing to unify composition‐architecture‐transport functionality to prevail at industrial conditions. Here, the morphological HEO electrode is introduced, a bioinspired framework integrating multielement mixing, architectural hierarchy, and surface adaptation. High‐throughput optimization identifies a critical nanosecond laser parameter window where rapid quenching traps metastable FeCoNiMoCrO x HEO nanoparticles foliage while Marangoni flows sculpt Ti microcone trunks. This structure exhibits superaerophobic‐superhydrophilic properties and exceptional oxygen evolution performance (η 10 = 188 mV). In an anion‐exchange membrane electrolyzer, the electrode achieves 1 A cm −2 at 1.82 V (surpassing commercial IrO 2 ‐coated Ti mesh), while maintaining stable operation for 600 h at 500 mA cm −2 (degradation rate: 38.33 µV h −1 ). DFT calculations confirm that Mo/Cr electronically modulates the primary OER active Ni sites via the M‐O‐M network, optimizing the d‐band center and favoring the Adsorbate Evolution Mechanism (AEM). This work establishes a paradigm for industrial electrocatalysts by encoding compositional complexity, structural coherence, and interfacial adaptability through morphological design, where multifunctionality emerges from multiscale synergy rather than isolated optimization.