钛柱撑蒙脱石光催化降解甲基橙的性能研究

Photocatalytic Degradation Performance of Titania Pillared Montmorillonite for Methyl Orange

以钛酸丁酯为前驱体、钠基蒙脱石为载体,采用溶胶-凝胶法制备了二氧化钛柱撑蒙脱石(TiO2-MMT)纳米复合材料。采用X-射线衍射仪、透射电子显微镜、全自动比表面积及中孔、微孔分析仪(BET)等分析手段对TiO2-MMT进行了表征,并研究了其对甲基橙的光催化降解活性。结果表明:TiO2-MMT主要由锐钛矿型TiO2和蒙脱石组成,呈层片状结构,TiO2柱撑到蒙脱石层间,并使其(001)晶面间距明显增大。在中性和碱性条件下,TiO2-MMT对甲基橙的光催化降解能力较弱;在酸性条件下,TiO2-MMT对甲基橙的降解率远远高于中性和碱性条件下的降解率。TiO2-MMT光催化降解甲基橙的优化条件为:pH值4、甲基橙初始浓度30mg.L-1、TiO2-MMT投加量10g.L-1,在优化条件下光照2h,TiO2-MMT对甲基橙的催化降解率为99.4%。

Titania pillared montmorillonite （TiO2-MMT） composite was prepared by a sol-gel approach, u- sing butyl titanate as precursor and Na-montmorillonite as support. The samples were characterized by X-ray diffraction,transmission electron microscopy, BET. Its photoeatalytic degradation performance for methyl or- ange （MO） was investigated by UV-Vis absorption spectrum. The results showed that the crystal phase of TiO2-MMT was composed of anatase and MMT,anatase particles lay in the interlayer space of MMT,and the lattice distance of the （001） plane of MMT was enlarged evidently. Photocatalytic degradation rate of TiO2- MMT for MO under acidic condition was much higher than that under neutral and alkaline conditions. The opti- mal photocatalytic degradation conditions of TiO2-MMT for MO were as follows.pH value of MO aqueous so- lution of 4,MO initial concentration of 30 mg·L-1 and TiO2-MMT dosage of 10 g·L-1. Irradiated for 2 h un- der above conditions,the photocatalytie degradation rate of MO was 99.4%.