A review of energy and environment electrocatalysis based on high-index faceted nanocrystals

Today, nanocrystals enclosed by high-index facets (HIFs) are attracting widely attentions of researchers due to their tremendous potential in the field of catalysis, especially in electrocatalysis, such as electro-oxidation of small organic molecule (such as formic acid, methanol, and ethanol), oxygen reduction reaction (ORR), hydrogen evolution reaction (HER), as well as the oxygen evolution reaction (OER). However, the practical applications of nanocrystals enclosed by HIFs still face many limitations in preparations of advanced electrocatalysts, including preparation strategy, limited life-time and stability. The development of advanced electrocatalysts enclosed with HIFs is crucial for solving these problems if the large-scale application of them is to be realized. Herein, we firstly detailedly demonstrate the identification methods of nanocrystals enclosed by HIFs, and then preparation strategies are elaborated in detail in this review. Current advanced nanocrystals enclosed by HIFs in electrocatalytic application are also summarized and we present representative achievements to further reveal the relationship of excellent electrocatalytic performance and nanocrystals with HIFs. Finally, we predict the remaining challenges and present our perspectives with regards of design strategies of improving electrocatalytic performance of Pt-based catalysts in the future.