Ti³⁺-doped TiO₂@C nanorods with enhanced photocatalytic performance under visible light

Ti3+-doped TiO2@C nanorods were prepared through a facile hydrothermal process. Na2Ti3O7 ultralong nanotubes and glucose were used as TiO2 precursor and carbon (C) source, respectively. During hydrothermal treatment, the hydrolysis of Na2Ti3O7 and polymerization of glucose induced the formation of TiO2 nanorods with a coating of carbon complex. At the same time, a part of Ti4+ was reduced to Ti3+ due to the rich hydroxyl groups in glucose. After calcination, an ultrathin carbon shell was formed on the surface of TiO2 nanorods. In this prepared composite, Ti3+ self-doped TiO2 nanorods work as photosensitizer to harvest solar energy to generate electron-hole pairs, the tight-binding interface between TiO2 nanorods and carbon shell works as electron transportation path, and the ultrathin carbon shell acts as electrons trapped and accumulated site. Photocatalytic test results indicate that Ti3+-doped TiO2@C nanorods exhibit higher activity and stability than TiO2 for photodegradation of methylene blue under visible light.