不同形貌ZnO@PANI纳米复合材料的制备及光催化性质

采用直接沉淀法和水热合成法制备出形貌和尺寸比较均一的颗粒状、棒状和球形花状的纳米ZnO。使用硅烷偶联剂KH-42(苯胺甲基三乙氧基硅烷,C₆H₅-NH-CH₂-Si(OCH₃)₃)对所得纳米ZnO进行表面化学修饰,修饰后的纳米ZnO(m-ZnO),经由皮克林乳液聚合法使苯胺单体在其表面聚合,形成聚苯胺(PANI)包覆的氧化锌纳米复合材料(m-ZnO@PANI),采用XRD、SEM、HRTEM、FTIR、UV-Vis、TG等对样品进行表征;研究了m-ZnO@PANI纳米复合材料对亚甲基蓝(MB)的光催化性能。结果表明,复合材料对可见光也有较强的吸收,在紫外、可见光照射下都有较好的光催化降解效率。其中,棒状ZnO纳米复合材料的光催化降解性能最好,它的紫外-可见光和可见光光催化降解率分别达到98.2%和97.1%,而且复合材料的光催化性能稳定,二次循环的紫外-可见光催化降解率仍达到96.0%。

Preparation and Photocatalytic Properties of Different Morphological ZnO@ PANI Nanocomposites

The particle, rod, and spherical flower-like nano-ZnO with the uniform morphology and size were prepared through a simple direct precipitation method and hydrothermal method. Then nano-ZnO was modified by the silane coupling agent anilino-methyl-triethoxysilane (KH-42) (m-ZnO), and the nanocomposites consisted of m-ZnO and polyaniline (m-ZnO@PANI) were synthesized by Pickering emulsion polymerization method. XRD, SEM, HRTEM, FTIR, UV-Vis, TG were used to characterize the shape, composition and structure of the nano-ZnO and m-ZnO@PANI nanocomposite. The photocatalytic activity of m-ZnO@PANI nanocomposites under UV-vis and visible light irradiation was evaluated by using nanocomposites as photocatalysts to degrade methylene blue (MB) dye molecules in aqueous solution. The results indicate that the nanocomposites have strong absorption of UV and visible light and good photocatalytic efficiency under UV-Vis and visible light irradiation. The photocatalytic efficiency of the rod nanocomposite is the best among them. The photodegradation rates under UV-Vis irradiation and visible light irradiation are 98.2% and 97.1% respectively. Furthermore, the recycled photodegradation efficiency of nanocomposite is stable and the second cycle photodegradation rate under UV-Vis irradiation was 96.0%.