Quenching induced Cu and F co-doping multi-dimensional Co3O4 with modulated electronic structures and rich oxygen vacancy as excellent oxygen evolution reaction electrocatalyst

The development of highly efficient non-precious electrocatalysts for the oxygen evolution reaction (OER) remains a significant challenge. In this work, we introduce a highly effective OER electrocatalyst, Cu-F-Co 3 O 4 , synthesized by doping copper (Cu) and fluorine (F) into Co 3 O 4 using a quenching method. Both experimental and theoretical calculations reveal that Cu and F incorporation significantly shifts the d-band center closer to the Fermi level, creates abundant oxygen vacancies, and facilitates the reconstruction of the catalyst to form the CuCo 2 O 4-y F y /CuO heterojunction. This structural modification enhances the OER performance of the catalyst. Additionally, the multi-dimensional architecture exposes more active sites and accelerates mass and charge transfer kinetics. The optimal catalyst, Cu-F-Co 3 O 4 -0.7, demonstrates a low overpotential of 290 mV at 10 mA·cm −2 , along with remarkable stability exceeding 100 h, significantly outperforming both pristine Co 3 O 4 and benchmark RuO 2 electrocatalysts. These findings offer new insights into activating surface reconstruction in spinel oxides by engineering both anion and cation defects for water oxidation.