Deeply understanding electrocatalytic oxygen evolution reaction from the perspective of defect structures

Defect including vacancies, doping, dislocations, outer surface, grain boundaries, phase interfaces, stacking faults, voids, etc., for enhanced oxygen evolution performance. [Display omitted] •The process of electrocatalytic OER is analyzed and important role of different defects is discussed and summarized.•The characterization and measurement techniques of defects are introduced and summarized.•The future research directions and challenges of defects in the field of OER are elaborated. Oxygen evolution reaction (OER), as a semi reaction of water splitting, CO2 reduction, etc., has been extensive attention. However, the OER process involves four electron proton coupling, and its sluggish kinetic process seriously affects the overall reaction efficiency. Various electrocatalysts, including precious metals Ir, Ru, and various non precious metal materials, have been continuously studied and improved to reduce OER overpotential and improve reaction efficiency. Defect engineering can effectively change the atomic coordination and electronic configuration of materials themselves, which is a powerful means of regulating performance. This review starts from analyzing the OER process and summarizes and discusses the key roles of different types of defects, as well as important techniques for characterizing and measuring defects. Finally, this review analyzes the challenges and potential development directions of future defects in regulating OER electrocatalysts.