Ir loaded Co(OH)2 nanosheets with vacancy defects for boosting oxygen evolution reaction and stability

[Display omitted] •Ir loaded Co(OH)2 nanosheets with vacancy defects were prepared with a facile method.•The charge transfer between Ir atoms and Co(OH)2 improves the OER kinetics.•The oxygen vacancy defects regulate the adsorption energy barrier of reaction intermediates.•The surface defect structure enhances the OER stability of the Ir/D-Co(OH)2 catalyst. Transition metal hydroxides have great potential as oxygen evolution reaction (OER) catalysts, while its low reaction kinetics and unsatisfactory stability limits the further application. Herein, Co(OH)2 nanosheets with oxygen vacancies defects and anchored Ir atoms and clusters (Ir/D-Co(OH)2) were prepared by electrochemical deposition and in-situ etching. The Introduction of Ir species is beneficial to regulate the valence electron configuration on Co 3d orbit and enhance the conductivity, which contributes to improving kinetics of Co(OH)2. In addition, the introduced defects not only regulate the adsorption energy barrier of reaction intermediates, but also serve as anchor centers for stabilizing Ir atoms and clusters, thus enhancing the active surface area and catalytic stability. The Ir/D-Co(OH)2/NF catalyst owns ultralow OER potential of 270.5 mV at 100 mA cm−2, and it has superior long-term stability under high current density of 100 mA cm−2 for 100 h. This work provides a simple method to design noble atoms loaded transition metal hydroxides with specific defects for enhancing OER performance and high stability.