色氨酸辅助合成光催化活性增强的球形纳米TiO2

以L-色氨酸（L-Trp）为生物模板，采用简单水解及煅烧后制备了球形结构TiO₂纳米光催化剂。通过X射线衍射、扫描电子显微镜、红外光谱、紫外-可见漫反射光谱、光致发光光谱和N₂吸附-解吸等方法对制得的TiO₂纳米材料进行表征。在催化剂合成过程中，L-Trp作为生物模板发挥至关重要的作用，能够指导球形结构纳米TiO₂的形成。考察了不同煅烧温度下制备的TiO₂样品光催化活性，结果表明550℃时制备的TiO₂样品具有优异的光催化活性，紫外光照射30min对甲基橙溶液的降解率达到95%左右，主要是由于较大比表面积和球形结构的协同效应。光催化剂稳定性实验表明，所制备的TiO₂纳米材料可作为一种实用有效的光催化剂用于紫外光照射下降解有机染料。同时，对L-Trp辅助下球形结构TiO₂纳米颗粒的可能生长机理进行讨论。

Tryptophan assisted synthesis of spherical nanometer TiO2with 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.