High-Entropy Alloy Nanomaterials with Well-Designed Nanostructures for Electrocatalytic Applications

High-entropy alloy (HEA) nanomaterials have emerged as promising electrocatalysts because of their compositional diversity and unique synergistic effects. Engineering the structure of HEAs, including facets, morphology, dimensions, and crystal phases, offers an effective strategy to further enhance their electrocatalytic performance. Such structural control provides a useful platform for unveiling the structure-performance relationships. This mini-review highlights recent advances in structural engineering of HEAs for electrocatalytic applications, with an emphasis on the structure formation mechanisms and structure-dependent catalytic performance. We first summarize representative synthetic strategies and discuss their advantages and limitations in the construction of well-defined HEA nanostructures. Then, we highlight the synthetic mechanisms of various HEA nanostructures and the functionalities of their unique structural characteristics in enhancing electrocatalysis. The structure-dependent performance of various HEA nanostructures in electrocatalytic reactions is reviewed from the perspectives of activity, selectivity, and durability. Finally, we discuss the current challenges and future opportunities for rationally designing next-generation HEA electrocatalysts.