Advancements in the in-situ growth of catalysts for water electrolysis: Substrate considerations, performance evaluations, and future perspectives

In-situ growth of catalysts for water electrolysis has gained significant advancements recently, it involves cultivating active electrocatalysts on conductive substrates such as metal foams and carbon-based materials, the latter play a pivotal role in influencing the morphology and architecture of catalysts and offer enhanced conductivity, abundant active sites, and improved mass transport. Numerous studies have predominantly focused on evaluating specific catalyst materials within various classifications and their preparation methods, but without addressing roles of supports. This review focuses on substrate considerations, performance evaluations, and prospectives. It provides a deeper understanding of the various strategies employed for in-situ growth of electrocatalysts and emphasizes the importance of different conductive substrates with case studies on the factors that affect catalytic activity. Furthermore, the prospects and challenges towards practical applications under some challenging conditions are highlighted. This review provides valuable strategies for the further development of rational design of catalyst–substrate as an enabling electrode.