Facile Oxidative Conversion of TiH2 to High-Concentration Ti3+-Self-Doped Rutile TiO2 with Visible-Light Photoactivity

TiO2, in the rutile phase with a high concentration of self-doped Ti3+, has been synthesized via a facile, all inorganic-based, and scalable method of oxidizing TiH2 in H2O2 followed by calcinations in Ar gas. The material was shown to be photoactive in the visible-region of the electromagnetic spectrum. Powdered X-ray diffraction (PXRD), transmission electron microscopy (TEM), ultraviolet-visible-near-infrared (UV-vis-NIR), diffuse reflectance spectroscopy (DRS), and Brunauer-Emmett-Teller (BET) methods were used to characterize the crystalline, structural, and optical properties and specific surface area of the assynthesized Ti3+-doped rutile, respectively. The concentration of Ti3+ was quantitatively studied by electron paramagnetic resonance (EPR) to be as high as one Ti3+ per similar to 4300 Ti4+. Furthermore, methylene blue (MB) solution and an industry wastewater sample were used to examine the photocatalytic activity of the Ti3+-doped TiO2 which was analyzed by UV-vis absorption, Fourier transform infrared spectroscopy (FT-IR), and electrospray ionization mass spectrometry (ESI-MS). In comparison to pristine anatase TiO2, our Ti3+ self-doped rutile sample exhibited remarkably enhanced visible-light photocatalytic degradation on organic pollutants in water.