In situ surface hydrogenation synthesis of Ti3+ self-doped TiO2 with enhanced visible light photoactivity

Abstract

A novel one-step, vapor-fed aerosol flame synthetic process (VAFS) has been developed to prepare Ti³⁺ self-doped titanium dioxide (TiO₂). The freshly formed TiO₂ was in situ surface hydrogenated during the condensation stage by introducing H₂ above the flame, and Ti³⁺ ions were created near the surface of TiO₂. The relative content of Ti³⁺ ions near the surface of TiO₂ is estimated to be 8%. Because of the high absorption of visible light and suppression of charge recombination, the photocurrent density and decomposition of MB under visible light irradiation were remarkably enhanced. This study demonstrates a simple, potential method to produce Ti³⁺ self-doped TiO₂ with effective photoactivity in visible light.