Wang Yu-Ping, Wang Lian-Jun, Peng Pan-Ying
School of Chemical Engineering, Nanjing University of Science and Technology, Nanjing 210094, China.
J Environ Sci (China). 2006;18(3):562-6.
TiO2 sol was prepared by sol-gel technique with tetrabutyl titanate as precursor. Supported TiO2 catalysts on activated carbon were prepared by soak and sintering method. The aggregation of nano-TiO2 particles can be effectively suppressed by added polyethylene glycol (PEG) as a surface modifier. The average particle diameter of TiO2, specific surface area and absorbability of catalyst can be modified. Based on characteristics of the TiO2 photocatalyst with XRD, specific surface area, adsorption valves of methylene blue and the amount of TiO2 supported on the activated carbon, the photocatalytic degradation of L-acid was studied. The effect of the factors, such as pH of the solution, the initial concentration of L-acid on the photocatalytic degradation of L-acid, were studied also. It was found that when the pH of the solution is 1.95, the amount of photocatalyst is 0.5 g, the concentration of the L-acid solution is 1.34 x 10(-3) mol/L and the illumination time is 7 h, the photocatalytic degradation efficiency of L-acid can reach 89.88%. The catalyst was reused 6 times and its degradation efficiency hardly changed.
以钛酸四丁酯为前驱体，采用溶胶 - 凝胶法制备TiO₂溶胶。通过浸泡和烧结法制备了负载在活性炭上的TiO₂催化剂。添加聚乙二醇（PEG）作为表面改性剂可有效抑制纳米TiO₂颗粒的团聚。TiO₂的平均粒径、催化剂的比表面积和吸附性能均可得到改善。基于TiO₂光催化剂的XRD特征、比表面积、亚甲基蓝吸附量以及负载在活性炭上的TiO₂量，研究了L - 酸的光催化降解。还研究了溶液pH值、L - 酸初始浓度等因素对L - 酸光催化降解的影响。结果表明，当溶液pH值为1.95、光催化剂用量为0.5 g、L - 酸溶液浓度为1.34×10⁻³ mol/L且光照时间为7 h时，L - 酸的光催化降解效率可达89.88%。该催化剂重复使用6次，其降解效率几乎不变。
