Department of Environmental Engineering, Faculty of Natural Resources and Environment, Science and Research Branch, Islamic Azad University, Tehran, Iran.
Department of Chemical and Petroleum Engineering, Sharif University of Technology, Tehran, Iran.
Water Sci Technol. 2019 Sep;80(5):864-873. doi: 10.2166/wst.2019.333.
This study focused on the synthesis of TiO-Zeolite nanocomposite through a sol-gel approach. The decrease in the size of the nanocomposite is considered a primary parameter to improve photocatalytic activity. In this regard, fabricated samples were exposed to laser irradiation (532 nm) for four different time intervals in order to investigate the size variation of the nanocomposite. FTIR, UV-Vis, XRD, DLS, SEM and EDX analyses were applied to characterize and determine the size of the products. An optimized nanocomposite sample, in term of the particle size, was used for photodegradation of 2,4-D herbicide from aqueous solution. Photodegradation was carried out under UV irradiation (12 W) and Xe lamp irradiation (200 W). The obtained results showed that laser irradiation time has a substantial effect on controlling the size of the nanocomposite. Results from the photocatalyst study indicated that the elimination of 2,4-D under the Xe lamp irradiation was higher compared with the UV irradiation. Also, the final synthesized nanocomposite exhibited higher catalytic activity for photodegradation of 2,4-D compared with pure Zeolite and pure anatase TiO samples. The reusability of TiO-Zeolite nanocomposite was studied in four successive cycles to evaluate the removal of 2,4-D under UV irradiation.
本研究通过溶胶-凝胶法合成了 TiO-Zeolite 纳米复合材料。纳米复合材料尺寸的减小被认为是提高光催化活性的一个主要参数。为此，将制备的样品暴露在激光照射（532nm）下四个不同的时间段，以研究纳米复合材料的尺寸变化。采用 FTIR、UV-Vis、XRD、DLS、SEM 和 EDX 分析对产物进行了表征和尺寸确定。根据粒径，优化了纳米复合材料样品，用于光降解水溶液中的 2,4-D 除草剂。光降解在 UV 照射（12W）和 Xe 灯照射（200W）下进行。结果表明，激光照射时间对控制纳米复合材料的尺寸有显著影响。光催化剂研究的结果表明，在 Xe 灯照射下 2,4-D 的消除率高于 UV 照射。此外，最终合成的纳米复合材料在光降解 2,4-D 方面表现出比纯沸石和纯锐钛矿 TiO 更高的催化活性。通过四周期的重复使用实验研究了 TiO-Zeolite 纳米复合材料的可重复使用性，以评估在 UV 照射下 2,4-D 的去除率。
