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

Abstract

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.