Enhancing Visible-Light Photocatalysis via Endohedral Functionalization of Single-Walled Carbon Nanotubes with Organic Dyes

The encapsulation of an organic dye, 10-phenylphenothiazine (PTH), in the inner cavity of single-walled carbon nanotubes (SWNTs) as a breaking heterogenization strategy is presented. The PTH@oSWNT material was microscopically and spectroscopically characterized, showing intense photoemission when illuminated with visible light at the nanoscale. Thus, PTH@oSWNT was employed as a heterogeneous photocatalyst in single electron transfer dehalogenation reactions under visible light irradiation. The material showed an enhanced photocatalytic activity, achieving turnover numbers as high as 3200, with complete recyclability and stability for more than eight cycles. Computational calculations confirm that electronic communication between both partners is established because, upon illumination, an electron of the excited PTH is transferred from the π system of the molecule to the delocalized π-cloud of the SWNT, thus justifying the enhanced photocatalytic activity.