Visible-Light-Driven Oxidative Coupling Reactions of Amines by Photoactive WS₂ Nanosheets

Visible-light-driven photocatalysis has been emerging as an efficient and sustainable approach for chemical transformation in organic reactions, in which photostable and cost-effective photosensitizers are required to trigger and promote it. Monolayer WS₂ nanosheets smaller than 120 nm were prepared by means of a modified liquid exfoliation method, and they showed strong photoluminescence in the visible range of the electromagnetic spectrum from 450 to 650 nm. These photoactive WS₂ nanosheets were exploited as photocatalysts in the oxidative coupling reactions of various amines under visible-light irradiation. They showed excellent photocatalytic activity and reusability without the loss of their catalytic activity in the visible-light-driven oxidative coupling reactions of various amines. In addition, the mechanism responsible for WS₂ nanosheet catalyzed imine production under visible-light irradiation was fully investigated.