In-situ formation of carboxylate species on TiO2 nanosheets for enhanced visible-light photocatalytic performance

It still remains challenge for expanding the photo-response range of TiO 2 with dominant {0 0 1} facets due to the hardly achieving modification of the electronic structure without destroying the formation of TiO 2 high energy facets. Herein, we report the construction of carboxylate species modified TiO 2 nanosheets with dominant {0 0 1} facets by employing ethanol as a carbon source through a low-temperature (300 °C) carbonization method. The as-obtained samples were investigated in detail by using various characterization techniques. The results indicate that the carboxylate species derived from the oxidation and carbonization of ethanol are coordinated to the {0 0 1} facets in a bidentate bridging mode. The electron-withdrawing carboxylate species induce TiO 2 to form a lower valence band edge and a narrower bandgap, which enhances the oxidation ability of photogenerated holes and expands the photo-response range. The partially carbonized carboxylate species can also act as a photosensitizer to induce visible-light photocatalytic activity of TiO 2 nanosheets. In addition, the carboxylate species can further promote the separation of photogenerated charge carriers. The findings of this work may provide a new perspective for tuning the band structure of TiO 2 with dominant {0 0 1} facets and improving its photocatalytic performance.