Hydrothermal Synthesis of Bi<sub>4</sub>Ti<sub>3</sub>O<sub>12</sub>/TiO<sub>2</sub> Composite

A hydrothermal processing technology was employed to synthesize Bi4Ti3O12/TiO2 composite by using TiO2 and Bi(NO3)3 as reactor precursors, and KOH as mineralizer. The microstructure and composition of the as-synthesized samples were characterized by X-ray diffraction (XRD), scan electron microscopy (SEM), and the photocatalytic activity was studied. The results showed that Bi/Ti molar ratio, mass of the KOH and the hydrothermal parameters play important roles on the morphology and activities of the photocatalyst. We could obtain composites with good morphology and better performance with 200 °C hydrothermal treatment for 12 h, 0.01 mol/L of KOH, and 1:2 of mole ratio of Bi/Ti, as well as using good crystalline TiO2 as the raw material. The as-prepared powder has a diameter of about 800nm, and the decolorized rate of methylene blue could reach 95 % after the UV-irradiation for 5 h.