Sonochemical synthesis and characterization of Cl-doped TiO2 and its application in the photodegradation of phthalate ester under visible light irradiation

Chlorine-doped anatase titanium dioxide (TiO2) nanocrystallites were prepared via a simple single-step method by sonicating a solution of tetraisopropyl titanate and sodium chloride in water/ethanol at 70°C. The as-prepared sample was characterized using X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy, and ultraviolet–visible spectroscopy. The presence of the chloride dopant is confirmed by the Cl 2p XPS peak with a binding energy of 198.2eV, which is assigned to the anionic Cl incorporated into TiO2. Cl-doping of TiO2 shifts the absorption edge toward a higher wavelength. The as-prepared samples were successfully used in the photodegradation of aqueous butyl benzyl phthalate (BBP) under visible light irradiation. The photodegradation rates of BBP reached 92% under visible light irradiation for 240min. BBP mineralization was also realized by further increasing the irradiation time.