Defect engineering on electrocatalysts for gas-evolving reactions.

The hydrogen evolution reaction (HER) and oxygen redox reaction, including the oxygen reduction reaction (ORR) and the oxygen evolution reaction (OER) are the core processes used for water splitting and in metal-air batteries. Thus, the design of electro-catalysts for use in the oxygen redox reaction and HER have received a lot attention around the world. Many strategies have been developed to improve these catalysts, including increasing the surface area, creating unique facet structures, enhancing the conductivities and so on. Among these improvements defect engineering on catalysts has been proven to be an effective and feasible way to accelerate the reaction rate. Herein, a short overview of the recent advances in defect engineering on electro-catalysts for ORR, OER and HER is presented, and the outlook for the defect engineering field is also summarized.