Efficient and Stable NiCo₂O₄/VN Nanoparticle Catalyst for Electrochemical Water Oxidation

Abstract

The oxygen evolution reaction (OER) is a critical step in water splitting to produce hydrogen. Therefore, the study of corresponding electrocatalysts for OER is of vital importance. However, the most-used carbon-based supports suffer from corrosion which leads to substandard performance. In this research, a series of vanadium nitrides (VN) were synthesized as supports for NiCo2O4. Compared with the pristine NiCo2O4 and NiCo2O4 supported on carbon black (NiCo2O4/C), the NiCo2O4 supported on the VN prepared in 800 °C (NiCo2O4/VN800) as a catalyst exhibits the best OER catalytic activity and stability. According to X-ray photoelectron spectroscopy and electrochemical characterizations, the good electrocatalytic performance of NiCo2O4/VN800 is ascribed to the high conductivity and good corrosion resistance of VN as well as the higher contents of Co2+ and Ni3+ on the catalyst surface owing to the interaction of VN and NiCo2O4.