Nickel-Doped Decatungstate as a Robust Photocatalyst for Violet Light-Triggered Redox Coupling Conversion of Alcohol and Water to Aldehyde/Ketone and Hydrogen.

The effective coupling of photoinduced alcohol oxidation and water reduction may economically produce hydrogen (H) from water, which is of great significance in solving the current energy crisis. This study discloses that decatungstate (DT) and especially Niions-doped DTs are active for the photoreaction of benzyl alcohol with HO, and under 48 h of violet light illumination, the best 1%Ni-DT yields ca. 86.1% benzoic acid and a 4.65 h H generation efficiency (turnover frequency, TOF). Also, 1%Ni-DT is efficient for the photoredox coupling reaction of aliphatic and especially aromatic primary/secondary alcohols with water. A series of characterizations support that the doubled-reduced HDT produced from the photoreaction plays a key role in water reduction to H, which is accelerated by the doped Ni. In particular, it and the derived Ni may construct a Z-type catalyst for water overall splitting, thereby hoisting the acid yield and H amount in the later stage of the photoreaction.