Etching to unveil active sites of nanocatalysts for electrocatalysis

Etching is an effective technique to expose catalytically active sites on the surface of nanocrystals by modifying the surface structure and composition. In this review, various physical and chemical etching methods, specifically developed for nanocrystal systems, as well as their advantages and disadvantages, are introduced. The surface changes in the etched nanocrystals are discussed in view of their impact on catalytic activity and stability to understand the relationship between the nanosurface and catalytic performance. Furthermore, we discuss the standing challenges and provide future research directions in this relevant field, which would lead to fruitful outcomes in developing highly stable and active electrocatalysts for sustainable energy technologies.