Tryptophan assisted synthesis of spherical nanometer TiO2 with enhanced photocatalytic activities

The spherical structure TiO2 nano photocatalyst was prepared by simple hydrolysis followed by calcination with L-tryptophan(L-Trp) as biological template. The prepared TiO2 was characterized by X-ray diffraction, scanning electron microscopy, infrared spectroscopy, UV-vis diffuse reflectance spectroscopy, photoluminescence spectroscopy, and N2 adsorption-desorption. The L-Trp played a crucial role in the formation of photocatalysts, which could induce the formation of spherical structure TiO2. The photocatalytic activity of TiO2 samples prepared at different calcination temperatures was investigated. The results showed that the TiO2 prepared at 550℃ exhibited an excellent photocatalytic activity, and the degradation rate of methyl orange(MO) solution reached about 95% under UV light irradiation in 30min, which was mainly due to the synergistic effect of large BET surface area and spherical structure. The results of photocatalytic stability test indicated that the prepared TiO2 nanomaterials could be used as practical and effective photocatalysts for the degradation of organic dyes under UV light irradiation. Furthermore, the possible growth mechanism of spherical structure TiO2 nanoparticles supported by L-Trp was discussed. © 2018, Chemical Industry Press. All right reserved.