Scalable anodic electrodeposition of efficient binder-free NiO electrocatalysts for water oxidation

چکیده مقاله

Developing high-performance, durable, and cost-effective electrocatalysts for the oxygen evolution reaction (OER) is pivotal for green hydrogen generation. In this research, the elctrocatalysts of the NiO nanostructures are directly electrodeposited onto a graphite substrate through a facile and binder-free anodic strategy. It was found that the applied deposition potential is a powerful electrochemical parameter to control the morphology, defect density, and the OER efficiency of the obtained NiO layers. The electrodeposition process, when performed at an optimized potential of 2.0 V, fabricates very tiny NiO nanoparticles that possess a high density of oxygen vacancies. This electrode fabricated at 2.0 V exhibits a proper OER activity in alkaline media, acquiring a high current density of 324 mA⋅cm− 2 at 1.8 V vs. RHE. After 24-h stability testing, the NiO-2 V electrode maintained a current density of ~200 mA/cm2 at 1.65 V vs. RHE, significantly outperforming the NiO-1 V electrode, which stabilized at only ~10 mA/cm2