Static-dynamic vacancies via pre-embedded heterogeneous Gd ions in RuO2/Gd-Co3O4 enabling robust water oxidation

Abstract

An in-depth understanding of the synergistic mechanisms among different types of vacancies is crucial for enhancing the electrocatalytic water splitting performance. Herein, we propose a straightforward “static-dynamic” vacancy strategy to achieve robust acidic water oxidation. Specifically, by pre-embedding heterogeneous Gd ions into Co₃O₄ substrates, static oxygen vacancies are introduced, while the subsequent leaching of Gd ions during the oxygen evolution reaction (OER) dynamically generates cation vacancies. Combining electrochemical probing with in situ synchrotron radiation infrared spectroscopy, we demonstrate that this dual-vacancy synergy optimizes the electronic structure and reaction pathways of the RuO₂-based electrocatalyst, leading to accelerated OER kinetics and enhanced stability of Ru active sites. The resulting RuO₂/Gd-Co₃O₄ exhibits an overpotential of only 193 mV at 10 mA cm⁻² and maintains exceptional durability over 72 hours. This feasible vacancy strategy provides a promising pathway for designing durable and efficient electrocatalysts for sustainable energy technologies.