Enhanced Photocatalytic Activity of B, N-Codoped TiO₂ by a New Molten Nitrate Process.

B, N-codoped titania mesoporous crystals were prepared by the sol-gel method followed by a molten nitrate process to modify the sample morphology. The composition, morphology and microstructure of the obtained samples were characterized by X-ray diffraction (XRD), X-ray photoemission spectroscope (XPS), Brunauer Emmett Teller (BET), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and selected area electron diffraction (SAED). Fourier Transform Infrared spectroscopy (FTIR) revealed weak complex vibrations between the Ti-O oxide species and the unsaturated sites (Ti3+) through the incorporation of hydroxyl groups, which was not observed in the bulk titania (B-N-TiO₂). The photocatalytic reactivity of boron-nitrogen codoped TiO₂ was examined for the removal of methylene blue (MB) under visible light irradiation. The nitrates treated B-doped TiO₂ exhibited better photocatalytic activity for dye degradation than that of B-doped TiO₂ and nitrates treated TiO₂. The best performance was obtained in the sample treated at a calcination temperature of 550 °C.