High-index faceted noble metal nanostructures drive renewable energy electrocatalysis

Noble metallic nanocrystals are used in a wide variety of applications, such as catalysis, batteries, and bio- and chemical sensors. Most of the previous studies focus on the preparation of thermodynamically stable nanocrystals enclosed by low-index facets and discuss their corresponding catalytic properties. Recently, researchers have found that the nanocrystals with high-index facets (HIFs) are of more interest for electrocatalysis. Herein, we review recent key progress in the synthesis of noble metallic nanoparticles enclosed with HIFs and their facet-dependent electrocatalytic behaviors. First, we introduce the concept of HIFs, and establish the correlation between their surface structure and catalytic activity. Then, we discuss various synthetic approaches for controlling the shapes and composition of the nanocrystals enclosed by HIFs. Afterwards, we showcase the enhanced electrocatalytic performance realized by HIF-based nanostructures. Finally, we provide guidance on how to improve the electrocatalysis by engineering HIFs on noble metallic nanocrystals.