含二氧化钛纳米复合膜的制备及对甲基橙的光催化降解

Fabrication of TiO_2-containing Nanocomposite Films and Their Photocatalytic Degradation for Methyl Orange

采用层层(LbL)自组装技术制备了含TiO2的复合膜。原子力显微镜(AFM)表征发现TiO2纳米粒子和磷钨酸聚阴离子被成功的组装到了复合膜中;以甲基橙染料废水的降解反应为模型,研究了纳米复合膜催化剂的光催化效率,发现(TiO2/PW12)n复合膜的光催化效率明显低于(PSS/TiO2)10,说明在pH值为6.4的近中性条件下,TiO2和PW12间没有表现出协同效应;同时考察了甲基橙初始浓度和复合膜中聚电解质层的影响。通过LbL技术把催化剂固载在玻璃片上解决了催化剂的回收问题,而且多层膜被重复使用四次后仍能保持较高的催化活性。

TiO2-containing nanocomposite films were prepared via an electrostatic layer-by-layer （LbL） self-assembly method. These LbL films were characterized by atomic force microscopy （AFM）. The results indicate that TiO2 and H3PW12040 （PWI2） were successfully incorporated into the nanocomposite films. The as-prepared （PSS/TiO2 ）10 films showed better photocatalytic performance than （TiO2/PW12）n films for the degradation of methyl orange （MO） solution at pH 6.4, which suggested that no synergistic effect between TiO： and PWj2 was found. The effect of initial concentration of MO solution and polyelectrolyte layers was also studied. Taking advantage of immobilization of catalysts on glass slides, the problem of recovery was solved. The nanocomposite films could be easily recovered and reused for several times with little decrease of MO conversion rate, indicating that they were stable under the ultraviolet （UV） irradiation.