Engineering Lower Coordination Atoms onto NiO/Co3O4 Heterointerfaces for Boosting Oxygen Evolution Reactions

Low-coordination atoms (LCAs) have been proven to play a critical role in boosting electrocatalysis. However, for enhancing catalytic activity, suitably engineering the LCAs in catalysts through rational design remains a challenge. Herein, we demonstrated self-supporting NiO/Co3O4 hybrids for advanced oxygen evolution reaction (OER) performance. Contributed to an abundance of heterointerfaces and increased oxygen vacancies at the interfaces, the numerous LCAs were generated in NiO/Co3O4. Consequently, the NiO/Co3O4 heterostructures exhibited an overpotential of only 262 mV at 10 mA cm–2 and a low Tafel slope of 58 mV dec–1. By employing density functional theory calculations, it was determined that the d electrons were effectively regulated. Moreover, the d-band centers of Co near the interface in NiO/Co3O4 were far from the Fermi level, thereby confirming the reduction of the unfavorable strong adsorption to oxo intermediates during the OER process. This study provides an effective approach for the rational construction of hybrid interfaces.