溶胶-凝胶法制备La^(3+)、碳纳米管掺杂纳米TiO_2及光催化性能

Preparation of La^(3+),Carbon Nanotube Doped Nanometer TiO_2 with Sol-Gel Method and Photocatalytic Activity of Doped Nanometer TiO_2

采用溶胶-凝胶法,分别制备了不同掺杂量的La3+掺杂TiO2、多壁碳纳米管掺杂TiO2及La3+与碳纳米管共掺杂纳米TiO2粒子.通过紫外光照射甲基橙溶液的光催化降解实验,研究了掺杂对TiO2光催化活性的影响.实验表明,适量的La3+掺杂可以提高TiO2的光催化活性,最佳掺杂浓度为La3+摩尔分数等于0.08%,碳纳米管掺杂也可以提高TiO2的光催化活性,La3+与碳纳米管共掺杂TiO2具有最高的光催化活性.10%(碳原子的摩尔分数)碳纳米管、0.08%La3+(摩尔分数)共掺杂TiO2在1 h内对甲基橙溶液的降解率达到84%,而纯TiO2在1 h内对甲基橙溶液的降解率只有约53%.X衍射图谱和透射电镜分析表明,制得的TiO2均为锐钛矿型,晶粒直径约为8~25 nm.

Three kinds of doped TiO2 particles, include La^3＋ doped, multi-wall carbon nanotube （MWCNT） doped and their co-doped TiO2, were prepared by sol-gel method. The catalytic activity of doped TiO2 was evaluated via ultraviolet light degradation experiments of methyl orange. It is found that La^3＋ doped TiO2 particles demonstrates a higher photocatalytic activity than that of pure TiO2, and an optimum value is reached at doped concentration of 0.08% （mole fraction）. CNT doped TiO2 can also improve the photocatalytic activity of TiO2. Besides, TiO2 particles codoped with La^3＋ and CNT show the highest photocatalytic activity. As for co-doped TiO2, the decomposition ratio of methyl orange solution reaches 84 % in 1 h, while it gets 53 % for pure TiO2. The microstructure of the particles is characterized with XRD and TEM techniques. These particles are endowed with anatase crystal phase of about 8-25 nm diameter.