PANI/AMTES-TiO2纳米复合材料的制备及其光催化性能

首先用偶联剂苯胺基甲基三乙氧基硅烷(AMTES)对纳米TiO2进行表面修饰(AMTES-TiO2), 然后通过苯胺单体在AMTES-TiO2表面的原位化学氧化接枝聚合, 制备了基于共价键结合的聚苯胺(PANI)/AMTES-TiO2纳米复合光催化材料. 用红外光谱(FTIR), X射线衍射(XRD), 热重分析(TGA), 紫外-可见漫反射光谱(UV-Vis-DRS)和荧光发射光谱(PL)等技术对复合材料进行了表征. 以亚甲基蓝(MB)为目标降解物, 研究了PANI/AMTES-TiO2复合材料在太阳光和紫外光下的光催化性能. 结果表明:聚苯胺敏化拓宽了TiO2的光谱响应范围, 复合材料在紫外和可见光区都有较强的吸收, 提高了光能的利用率和光生载流子的分离效率, 使复合材料表现出较高的光催化活性; 苯胺与AMTES-TiO2的质量比(w)对复合材料的光催化活性有较大影响, 当w为0.025时, 复合材料在两种光源下的催化性能均优于TiO2和AMTES-TiO2.

Preparation and Photocatalytic Activity of PANI/AMTES-TiO2 Nanocomposite Materials

After TiO2 nanoparticles were surface modified by the coupling agent anilinomethyltriethoxysilane (AMTES-TiO2), polyaniline (PANI) was grafted onto the surface of the AMTES-TiO2 nanoparticles by in situ chemically oxidative polymerization resulting in a PANI/AMTES-TiO2 nanocomposite photocatalyst. PANI and TiO2 are linkaged by chemical bonds. The nanocomposites were characterized using Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), X-ray diffraction (XRD), UV-Visible diffuse reflectance spectrum (UV-Vis-DRS) and photoluminescence (PL). The photocatalytic activity was evaluated by the degradation of methylene blue (MB) in aqueous solution under UV and solar light irradiation. Results show that the sensitizing effect of PANI can improve the light response of TiO2 and enhance the separation efficiency of electron and hole pairs which in turn promotes the photocatalytic ability of the nanocomposites. The mass ratio (w) of aniline to AMTES-TiO2 has a significant effect on the photocatalytic activity of nanocomposites and the optimal activity is obtained when the w is 0.025.