Enhanced photocatalytic CO reduction with defective TiO nanotubes modified by single-atom binary metal components.

A binary component catalyst consists of single atoms (SAs- Pt and Au) anchored on self-doped TiO nanotubes (TNTs), was developed for photocatalytic CO reduction. The defects introduced TNTs substrate was stabilized with atomic Pt and Au via strong metal support interactions (MSI), due to which, the covalent interactions facilitated an effective transfer of photo-generated electrons from the defective sites to the SAs, and in turn an enhanced separation of electron-hole pairs and charge-carrier transmission. The Pt-Au/R-TNTs with 0.33 wt% of SA metals, exhibited a maximum of 149 times higher photocatalytic performance than unmodified R-TNT and a total apparent quantum yield (AQY) of 17.9%, in which the yield of CH and CH reached to 360.0 and 28.8 μmol g h, respectively. The metals loading shifted the oxidation path of HO from •OH generation into O evolution, that inhibited the self-oxidization of the photocatalyst.