Structural advantages and enhancement strategies of heterostructure water-splitting electrocatalysts

As an environmentally friendly and resource-rich energy, hydrogen is recognized as an ideal alternative to conventional fossil fuels. Among various methods for hydrogen production, electrochemical water splitting is one of the most promising approaches, for which hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) are crucial for determining the performance. Recently, much research has shown heterostructure catalysts to possess competitive electrocatalytic performance toward HER and OER. However, compared with their theoretical activities, many heterostructure catalysts remain somewhat unsatisfactory and have a long way to go. With the aim of ultimately enhancing electrocatalytic performance, recent approaches for the modification of heterostructure catalysts are summarized in this review. Typical synthetic strategies, such as design of nanostructure, chemical doping, and heterostructure-based hybrids synthesis, are discussed, and their advantages are highlighted. Finally, perspectives on the future direction of heterostructure electrocatalysts toward water splitting are presented.