Synergistic Activation Mechanism of Multidefect Structures in Atomically Thin Oxygen Evolution Electrocatalysts

Amidst the global imperative for clean energy transition, electrocatalytic water splitting faces efficiency constraints due to sluggish oxygen evolution reaction (OER) kinetics. While defect engineering enhances OER catalysis, conventional single-/dual-defect systems have inherent optimization limitations. Herein, we engineer atomically thin CoOOH nanosheets as programmable carriers for a triple-defect coordination system (Mn 2+ /W 6+ dopants with Co vacancies). This unique ultrathin architecture, integrating heteroatom dopants and cationic vacancies, overcomes conventional characterization barriers by enabling atomic-scale imaging. Advanced structural analysis directly visualizes and confirms the multidefect configurations. Electrochemical assessment demonstrates exceptional activity (overpotential: 286 mV @ 10 mA cm –2 ) and stability (>100 h), while density functional theory (DFT) calculations reveal the mechanism of multidefect-synergy intermediate binding energy optimization─positioning the Gibbs free energy change of O (Δ G O ) nearly midway between Δ G OH and Δ G OOH . This work establishes a paradigm for rational electrocatalyst design by visualizing atomic-level multidefect interplay.