月桂酸调控制备高光催化活性TiO_2纳米晶

Synthesis of TiO_2 Nanocrystallites With High Photocatalytic Performance in the Presence of Lauric Acid

以钛酸丁酯为钛源、月桂酸为添加剂,采用简单溶剂热法合成了TiO_2纳米晶。结合XRD与TEM手段,以光催化降解亚甲基蓝染料为探针反应,考察了月桂酸与钛酸丁酯的摩尔比以及温度对所合成的TiO_2纳米晶的结构及其光催化性能的影响,并探讨了该体系下TiO_2纳米晶的生长机理。结果表明,月桂酸的存在有利于提高所合成TiO_2的结晶度,适当的月桂酸与钛酸丁酯的摩尔比是制备催化活性较高的TiO_2的必要条件;随着合成温度的升高,所得TiO_2的晶型由纯锐钛矿型向锐钛矿与金红石混合型转变,在200℃时所制备的TiO_2纳米晶的形貌规则、分散性高、光催化活性好。在月桂酸合成体系中,TiO_2晶粒生长符合定向吸附生长机制。

By using tetrabutyl titanate as Ti source, TiO2 nanocrystallites were successfully synthesized through a solvothermal route in the presence of laurie acid. The effects of the parameters, such as the molar ratio of laurie acid to tetrabutyl titanate and the synthesis temperature, on the structure of the obtained TiO2 were investigated by XRD and TEM techniques. And their photocatalytic activities were evaluated for the degradation of ethylene blue dye. In addition, the growth process of TiO2 nanoerystallites was discussed. The experimental results indicated that the addition of laurie acid could improve the crystallinity of the obtained TiO2 and the proper ratio of tetrabutyl titanate to lauric acid was crucial for the preparation of high photocatalytie TiO2. With the increase of temperature, the crystal structure of the obtained TiO2 transformed from pure anatase type to mixed type. The TiO2 obtained at 200℃ exhibited regular morphology, good dispersibility and high photocatalytic performance. The growth of TiO2 nanocrystallites prepared with laurie acid followed OA growing mechanism.