Characterization and photoactivity of TiO2 sols prepared with triethylamine

Using triethylamine as a surface protective agent, a transparent and pale yellowish TiO2 sol had been prepared at 90 °C. This method was very different from the traditional methods, which produced titanium dioxide nanoparticles with anatase crystalline structure either at high acid condition or high temperature. X-ray diffraction (XRD) and transmission electron spectroscopy (TEM) demonstrated that the as-prepared TiO2 sol nanoparticles with anatase crystalline structure were uniformly distributed, and the average size was 3 nm. X-ray photoelectron spectroscopy (XPS) and UV–vis absorption spectra showed that triethylamine was adsorbed on TiO2 sol particles surface. FTIR spectroscopy noted that TiO2 sol particles had the similar spectra with Degussa P25. Photoactivity of the as-prepared TiO2 sol was studied by investigating the photodegradation of methyl violet in hydrosol reaction system under visible light irradiation.