A mesoporous TiO2−xNx photocatalyst prepared by sonication pretreatment and in situ pyrolysis

A novel method for preparing a visible-light-driven mesoporous TiO2−xNx photocatalyst has been developed. It involves the in situ pyrolysis of the product from a chelation reaction under sonication between TiCl4 and ethylenediamine in an ethanol solution of the triblock copolymer F127. The as-prepared photocatalysts exhibit very strong photoactivity in the photocatalytic oxidation of methylene blue under irradiation in the visible spectral region. The samples were characterized by spectroscopic techniques including ultraviolet–visible light reflectance (UV–vis), X-ray photoelectron spectroscopy (XPS), electron spin resonance (ESR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The effects of ultrasound on the physicochemical properties and photoactivity of mesoporous TiO2−xNx are discussed based on the characterization results.