Oxysulfide Semiconductors for Photocatalytic Overall Water Splitting with Visible Light

Photocatalytic overall water splitting by sulfide-based materials is a great challenge because of the poor resilience of such materials against hole oxidation. In a recent study, Domen and co-workers developed an innovative strategy to stabilize sulfide-based photocatalysts by hybridizing S 3p with O 2p orbitals to produce oxysulfides in which S²⁻ is stable. Further surface engineering of the oxysulfides with dual co-catalysts promoted charge separation and interface transfer, thus reducing the charge build-up that inhibits photocorrosion. The pH value of the reaction mixture is a critical consideration for achieving efficient stoichiometric H₂ and O₂ evolution by these oxysulfide photocatalysts.