A novel single-mode microwave assisted synthesis of metal oxide as visible-light photocatalyst

Visible-light photocatalyst titanium dioxide (TiO2) was successfully prepared via a novel and facile single-mode microwave assisted synthesis process. In this one-step synthesis, Ti as target material selectively oxidizes in magnetic field throughout rapid heating, whose process requires less energy consumption and short time. In obtained TiO2, self-doping of Ti3+ was confirmed, which makes TiO2 perform sufficient light absorption in visible region with wavelength above 400 nm. Such Ti3+ self-doped TiO2 exhibits much narrower optical bandgap (2.14 eV) with compared stoichiometric TiO2 (3.0-3.2 eV). The synthesized TiO2 also shows superior photocatalytic activity to commercially available TiO2 towards the degradation of Rhodamine B under visible light irradiation.