Metal chalcogenide-based photoelectrodes for photoelectrochemical water splitting

Photoelectrochemical water splitting (PEC-WS) is a promising technique for transforming solar energy into storable and environmentally friendly chemical energy. Designing semiconductor photoelectrodes with high light absorption capability, rapid e−/h+ separation and transfer, and sufficient chemical stability is vital for developing an efficient PEC-WS system. Metal chalcogenides (MCs) have emerged as promising candidates for light absorbers because of their unique electrical and optical characteristics. In this review, we present recent developments in hydrogen generation via PEC-WS using MC-based photoelectrodes. First, we present a simple illustration of PEC-WS fundamentals. Second, the current performance of various metal (mono-, di-, and tri-) chalcogenide/semiconductor photoelectrodes in PEC-WS is summarized. Then, the charge transfer mechanism at the MC/semiconductor interface and the PEC-WS mechanism is thoroughly explained. Finally, we discuss future research perspectives toward developing efficient and stable MC/semiconductor photoelectrodes.