Ionic liquid derived electrocatalysts for electrochemical water splitting

Hydrogen production from electrochemical water splitting is a promising strategy to generate green energy, which requires the development of efficient and stable electrocatalysts for the hydrogen evolution reaction and the oxygen evolution reaction (HER and OER). Ionic liquids (ILs) or poly(ionic liquids) (PILs), containing heteroatoms, metal-based anions, and various structures, have been frequently involved as precursors to prepare electrocatalysts for water splitting. Moreover, ILs/PILs possess high conductivity, wide electrochemical windows, and high thermal and chemical stability, which can be directly applied in the electrocatalysis process with high durability. In this review, we focus on the studies of ILs/PILs-derived electrocatalysts for HER and OER, where ILs/PILs are applied as heteroatom dopants and metal precursors to prepare catalysts or are directly utilized as the electrocatalysts. Due to those attractive properties, IL/PIL-derived electrocatalysts exhibit excellent performance for electrochemical water splitting. All these accomplishments and developments are systematically summarized and thoughtfully discussed. Then, the overall perspectives for the current challenges and future developments of ILs/PILs-derived electrocatalysts are provided.