硅胶负载氯掺杂二氧化钛光催化剂的水热制备与光催化活性评价

利用水热法, 以硅胶为载体, 以Ti(SO4)2为钛源, NaCl为氯源制备了具有良好性能的硅胶负载氯掺杂二氧化钛(CTS)光催化剂, 考察了氯投加量、焙烧温度及钛硅比对光催化活性的影响. 结果表明, 氯投加量为15% (nCl/nTi)、钛硅物质的量比为3:1、焙烧温度为750 ℃时制备的CTS具有最佳的光催化活性, 其比表面积为60.8 m2·g-1. CTS中的硅胶除了作为载体, 还起到了促进锐钛矿二氧化钛的生成并抑制其向金红石相转变的作用; 氯掺杂二氧化钛(CT)经硅胶负载后, 其表面孔结构发生了变化, 并且热稳定性增加. 苯酚降解实验表明, 与CT相比, CTS以0.7740 g·g-1的二氧化钛含量具有更高的光催化活性.

Hydrothermal Preparation and Photocatalytic Activity of Chlorine Doped Titanium Dioxide Supported on SiO_2

A chlorine doped titanium dioxide photocatalyst was synthesized by a hydrothermal process using silica gel as a carrier,Ti(SO_4)_2 as a Ti source，and NaCl as a Cl source．We discuss factors such as the doping ratio of chlorine to titanium,the calcination temperature，and the ratio of titanium to silicon,all of which influence the photocatalytic activity of the sample．We found that the best chlorine to titanium ratio(n_o/n_(Ti))was 15％．the best calcination temperature was 750℃，and the best ratio of titanium to silicon(n_(Ti)/n_(Si))，was 3：1．The BET surface area of the chlorine doped titanium dioxide supported on SiO_2(CTS)was60．8m~2·g~(-1)．No rutile phase of TiO_2 was formed in the CTS after calcination at high temperature indicating that the presence of silica inhibited the phase transformation of TiO_2 from anatase phase to rutile phase．It also influences the structural and textural properties of the chlorine doped titanium dioxide(CT)．A phenol degradation test showed that the photocatalytic activity of the CTS Was better than that of the CT although the TiO_2 concentration in the CTS was 0．7740 g·g~(-1),which was less than that of the CT．