氯掺杂二氧化钛柱撑蒙脱土的合成及光催化性能

Synthesis and Photocatalytic Activities of Chlorinedoped TiO_2 Pillared Montmorillonite

采用溶胶-凝胶法制备了氯掺杂二氧化钛柱撑蒙脱土催化剂。利用XRD、SEM、UV-Vis-DRS、光致发光谱(PLS)、N2吸附-脱附和XPS等测试技术对其进行了表征。结果表明,该催化剂具有明显的锐钛矿相结构,且氯掺杂与二氧化钛柱撑后,蒙脱土的层间结构没有完全被破坏;氯掺杂拓宽了其光吸收范围,在可见光区吸收增强;其带隙能由3.19 eV减小至3.14 eV;氯以阴离子形式存在于TiO2晶格中。对硝基苯胺降解实验表明,氯掺杂可显著提高二氧化钛柱撑蒙脱土的光催化活性,氯掺杂量为6%(与钛的摩尔比)的催化剂具有较好光催化活性。

Chlorine-doped titanium pillared montmorillonite （Cl-TM） was prepared by the sol-gel technique in order to improve the photocatalytic activity. X-ray diffraction （XRD）, scanning electron microscope （SEM）, energy dispersive spectroscopy （EDS）, UV-Vis diffuse reflectance spectroscopy （UV-Vis-DRS）, photoluminescence spectrometer （ PLS）, X-ray photoelectron spectroscopy （ XPS ） , fourier-transform infrared spectroscopy（FT-IR）, N2 adsorption-desorption （BET） were used to characterize the products. The results show that the products had typical anatase phase while keeping the pillared structure of montmorillonite. The presence of montmorillonite can inhibite the phase transformation of titania from anatase to rutile. In addition, Chlorine-doped sample can reduce the band gap energy of TiO2 from 3.19 eV to 3.14 eV and therefore extend the light response of TiO2 to visible light region. XPS data imply that chlorine existed in the TiO2 crystal lattice as an anion. Furthermore, the photocatalytic degradation of PNA by Cl-TM indicates that the activity was significantly affected by chlorine-doped amount, and the optimized content is 6% （ molar ratio of Cl to Ti）.