The emerging role of ionic liquids (ILs) and deep eutectic solvents (DESs) in the synthesis of cobalt-based catalysts for water splitting is reviewed. ILs and DESs can serve as solvents and templates due to their unique physicochemical properties. They can efficiently dissolve raw materials and provide a special nucleation and growth environment, obtaining catalysts with novel structures. The designability of ILs and DESs allows for the controlled preparation of catalysts, where they can participate in the reaction as reactants, providing elements such as P, S, N, simplifying the preparation system of cobalt phosphide, sulfide, and nitride. ILs and DESs in catalyst synthesis achieve structural and compositional design, impacting surface adsorption and intermediate stability, allowing precise control over reaction paths and product selectivity. This leads to improved catalytic performance and stability. The review aims to succinctly summarize recent progress and guide researchers in selecting superior solvents for catalyst preparation.
Bai et al. (Sun,) studied this question.