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.