掺铂有机-钛柱撑膨润土复合材料的吸附和光催化性能研究

采用阳离子表面活性剂十六烷基二甲基溴化铵对临安膨润上进行改性修饰，以钛酸丁酯和K2P1Cl6为前驱体，利用掺有小同量铂的TiO2溶胶对改性膨润土进行反应，制得一系列掺铂有机-钛柱撑膨润土复合材料。测定了复合材料的BET比表面积，利用X射线粉末衍射（XRD）、扫描电子显微镜（SEM）和能量分散光谱（EDS）等手段对其微观结构进行了表征。以甲基橙染料为目标污染物，考察了复合材料的吸附能力和光催化活性。实验结果表明，掺铂的有机-钛柱撑膨润土复合材料比未掺铂的复合材料具有较好的层状结构，且对甲基橙的吸附能力较佳。由于铂能够充当捕获载流子的陷阱，能够有效抑制TiO2光生电子-空穴的复合，所以掺铂有机-钛柱撑膨润土复合材料具有更好的光催化性能，其中掺铂量为0．2％的复合材料的光催化活性最佳，对甲基橙的降解效果最好。

The adsorption performance and photocatalytic activity of Pt-TiO2 pillared clays composite modified by surfactants

Pt_TiO_2 pillared clays were prepared by the Sol_gel method at a certain ratio of Ti(OC_4H_9)_4 to CH_3COOH modified by cationic surfactant cetyltrimethyl ammonium bromide (CTMAB). These composite catalysts were prepared by adding surfactant first, and then pillared with TiO_2 sol solution which was prepared in different Pt contents. Scanning electron microscopy (SEM), X_ray diffraction (XRD) and energy dispersive spectrometry (EDS) were used to investigate the texture of prepared catalysts, and their BET surface areas were also measured. The adsorption and photocatalytic performance of prepared pillared clays were studied by using methyl orange(MO) as a mode organic pollutant. The result indicated that the catalysts obtained layered struc_tures. And the different adsorptions with different contents of Pt were observed. Moreover,the conclusion is reached that Pt can act as separation centers which capture the photogenerated electrons and make a longer electron_hole pair separation lifetime. So it is found that different photocatalytic properties can be enhanced by preparing the catalyst with different Pt contents. An optimal content of 0.2% Pt can achieve the best photocatalytic performance of MO.