The hydrothermal synthesis of mesoporous TiO2 with high crystallinity, thermal stability, large surface area, and enhanced photocatalytic activity
The hydrothermal synthesis of mesoporous TiO2 with high crystallinity, thermal stability, large surface area, and enhanced photocatalytic activity
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DOI：
10.1016/j.apcata.2007.02.010
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发表时间：
2007-04-30
影响因子：
5.5
通讯作者：
Kwak, Seung-Yeop
中科院分区：
文献类型：
--
作者：
Kim, Dong Suk;Kwak, Seung-Yeop
采用简单的溶胶-凝胶方法在水溶液中将聚乙二醇-聚丙二醇三嵌段共聚物和异丙醇钛与 2,4-戊二酮混合，制备出形状良好的球形介孔 TiO2。进行水热处理以提高介孔TiO2的结晶度、热稳定性、表面积和光催化活性。研究发现，经过水热处理的介孔TiO2材料即使在合成状态下也具有高结晶度，具有纳米晶锐钛矿结构，而未处理的材料在300℃煅烧之前具有非晶态或半晶相。经水热处理的介孔TiO2的表面积超过395 m(2) g(-1)，而未处理材料的表面积小于123米（2）克（-1）。发现经过水热处理的介孔 TiO2 材料的孔径分布比未处理的材料更窄；随着煅烧温度的升高，平均孔径从5.7纳米增加到10.1纳米。水热处理的介孔TiO2的光催化活性显着高于未处理材料的活性，其最大分解速率比商业TiO2 P25快三倍。介孔TiO2 的高光催化活性归因于水热处理诱导的纳米晶锐钛矿的大表面积和高结晶度。 (C) 2007 Elsevier B.V 保留所有权利。
Well-defined spherical mesoporous TiO2 was prepared from a poly(ethylene glycol)-poly(propylene glycol)-based triblock copolymer and titanium isopropoxide mixed with 2,4-pentanedione by using a simple sol-gel approach in aqueous solution. Hydrothermal treatment was performed to increase the crystallinity, thermal stability, surface area, and photocatalytic activity of the mesoporous TiO2. The hydrothermally treated mesoporous TiO2 materials were found to have a high crystallinity with a nanocrystalline anatase structure even in the as-synthesized state, whereas untreated materials were found to have an amorphous or semicrystalline phase prior to calcination at 300 degrees C. The surface area of hydrothermally treated mesoporous TiO2 was found to exceed 395 m(2) g(-1), whereas the areas of the untreated materials were less than 123 m(2) g(-1). The pore size distributions of the hydrothermally treated mesoporous TiO2 materials were found to be narrower than those of untreated materials; the average pore size increased from 5.7 to 10.1 nm with increases in the calcination temperature. The photocatalytic activity of hydrothermally treated mesoporous TiO2 is significantly higher than the activities of untreated materials, with a maximum decomposition rate that is three times faster than that of a commercial TiO2, P25. The high photocatalytic activity of mesoporous TiO2 is due to the large surface area and high crystallinity with a nanocrystalline anatase that is induced by the hydrothermal treatment. (C) 2007 Elsevier B.V All rights reserved.