聚丙烯酸固载纳米TiO_2复合材料的制备及其光催化性能

Preparation of poly(acrylic acid)-supported nanoscale TiO_2 and its photocatalytic activity

采用改进的溶胶-凝胶法制备了水溶性TiO2干凝胶,利用交联聚丙烯酸(PAA)强吸水性和三维网状结构特点,将TiO2溶胶粒子固载到聚丙烯酸高分子链上,经过水热处理原位生长制备PAA/TiO2纳米复合材料。通过拉曼光谱(Raman)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)等测试手段研究PAA/TiO2纳米复合材料的结构特征,以甲基橙为模型污染物研究了PAA/TiO2纳米复合材料的光催化性能。结果表明,纳米TiO2粒子被固载到PAA高分子链上,PAA吸水膨胀后扩展至整个反应空间,有效地增加了纳米TiO2与有机污染物的接触面积,大大提高了光催化降解的效率。

Poly（acrylic acid） （PAA）-supported nanoscale TiO2 has been prepared using a soluble titania xerogel, which was synthesized via a modified sol-gel method. TiO2 nanoparticles were immobilized on PAA macromolecular chains by in situ growth with a hydrothermal treatment. Raman spectroscopy, scanning electron microscopy and transmission electron microscopy were used to investigate the nanostructure of the PAA/TiO2 nanocomposites. The photocatalytic activity of PAA/Ti02 nanoeomposites was evaluated using photodegradation of methyl orange as a probe reaction. The results showed that TiO2 supported on PAA had a high photoactivity. This may be because PAA chains immobilized TiO2 can expand thousands of times after absorbing water, leading to increase in the interracial area between TiO2 and organic pollutants. Meanwhile, the as-prepared PAA/TiO2 nanocomposites can be easily re- covered from purified water with a low cost.