Pure and Applied Chemistry

Abstract: Phase-pure brookite TiO₂ and its activity has been obscured for its difficulty of synthesis. Hence, we introduced the method of preparation and property of phase-pure brookite TiO₂ and prepared phase-pure brookite TiO₂ by hydrothermal method using Ti(SO₄)₂ as precursor. Phase formation was achieved by hydrothermal treatment at 180 °C after different synthesis time. The physical and photophysical properties of samples were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), UV–vis diffraction (UV–vis/DRS), and Raman spectroscopy. The dependence of the photocatalytic activities on synthesis time and correlations with the physical properties of brookite samples was examined in detail. In the case of mineralization of rhodamine B (Rh B), the sample with the narrowest bandgap and the lowest photoluminescence (PL) intensity (at hydrothermal synthesis time 36 h) showed the best photodecolorization activity. Proposed decolorization mechanism was elucidated in the light of the UV–vis spectra of the analyzed degradation products and frontier electron density (FED) theory. The results indicated that photocatalytic decolorization by brookite TiO₂ is a highly effective way to remove Rh B under near-visible light irradiation.