Visible-Light Overall Water Splitting by CdS/WO₃/CdWO₄ Tricomposite Photocatalyst Suppressing Photocorrosion

Photocatalytic water splitting under visible light has attracted attention as a possible solution to the energy exhaustion problem. Hitherto, water splitting has been generally achieved using several oxynitrides, oxysulfides, and nitrides, and only a few studies report water splitting using cadmium sulfide (CdS) as a photocatalyst. A major reason for this is that CdS undergoes photocorrosion. In this study, we achieved an overall water splitting under visible light using a CdS/WO3/CdWO4 tricomposite photocatalyst. In the process, photocorrosion of CdS was suppressed by covering it with WO3 and CdWO4, and the oxidation reaction progressed in WO3 by the Z-scheme type photocatalytic reaction.