Plasma?induced Mo?doped Co ₃ O ₄ with enriched oxygen vacancies for electrocatalytic oxygen evolution in water splitting

Heteroatomic substitution and vacancy engineering of spinel oxides can theoretically optimize the oxygen evolution reaction (OER) through charge redistribution d-band center modification but still remain a great challenge in both preparation catalytic mechanism. Herein, we proposed novel efficient Ar-plasma (P)-assisted strategy to construct heteroatom Mo-substituted vacancies enriched hierarchical Co3O4 porous nanoneedle arrays situ grown on carbon cloth (denoted P-Mo-Co3O4@CC) improve OER performance. technology efficiently generate sites at surface hydroxide, which induces anchoring Mo anion salts electrostatic interaction, finally facilitating atoms formation surface. The P-Mo-Co3O4@CC affords low overpotential only 276 mV 10 mA cm?2 for OER, is 58 superior that Mo-free Co3O4@CC surpasses commercial RuO2 catalyst. robust stability satisfactory selectivity (nearly 100% Faradic efficiency) are also demonstrated. Theoretical studies demonstrate with variable valance states regulates atomic ratio Co3+/Co2+ increases number vacancies, thereby inducing tuning Co3O4, adsorption energy intermediates (e.g., *OOH) during OER. Furthermore, two-electrode OER//HER electrolyzer equipped as anode displays operation potential 1.54 V deliver current density cm?2, exhibits good reversibility anticurrent fluctuation ability under simulated real supply conditions, demonstrating water electrolysis.