Oxygen vacancies and V co-doped Co3O4 prepared by ion implantation boosts oxygen evolution catalysis*

Introducing heteroatoms and defects is a significant strategy to improve oxygen evolution reaction (OER) performance of electrocatalysts. However, the synergistic interaction of the heteroatom and defect still needs further investigations. Herein, we demonstrated an oxygen vacancy-rich vanadium-doped Co3O4 (V-Ov-Co3O4), fabricated by V ion implantation, could be used for high-efficient OER catalysis. X-ray photoelectron spectra (XPS) and Density functional theory (DFT) calculations show that the charge density of Co atom increased, and the reaction barrier of reaction pathway from O* to HOO* decreased. V-Ov-Co3O4 catalyst shows a low overpotential of 329 mV to maintain current density of 10 mA cm-2, and a small Tafel slope of 74.5 mV dec-1. This modification provides us with valuable perception for future design of heteroatom-doped and defect-based electrocatalysts.