Research progress on electronic and active site engineering of cobalt-based electrocatalysts for oxygen evolution reaction

Electrocatalytic water splitting has been identified as a potential candidate for producing clean hydrogen energy with zero carbon emission. However, the sluggish kinetics of oxygen evolution reaction on the anode side of the water-splitting device significantly hinders its practical applications. Generally, the efficiency of oxygen evolution processes depends greatly on the availability of cost-effective catalysts with high activity and selectivity. In recent years, extensive theoretical and experimental studies have demonstrated that cobalt (Co)-based nanomaterials, especially low-dimensional Co-based nanomaterials with a huge specific surface area and abundant unsaturated active sites, have emerged as versatile electrocatalysts for oxygen evolution reactions, and thus, great progress has been made in the rational design and synthesis of Co-based nanomaterials for electrocatalytic oxygen evolution reactions. Considering the remarkable progress in this area, in this timely review, we highlight the most recent developments in Co-based nanomaterials relating to their dimensional control, defect regulation (conductivity), electronic structure regulation, and so forth. Furthermore, a brief conclusion about recent progress achieved in oxygen evolution on Co-based nanomaterials, as well as an outlook on future research challenges, is given.