Excellent photocatalytic degradation activities of ordered mesoporous anatase TiO₂-SiO₂ nanocomposites to various organic contaminants

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• 作者：Weiyang Dong ; Yaojun Sun ; Qingwei Ma ; Li Zhu ; Weiming Hua ; Xinchun Lu ; Guoshun Zhuang ; Shicheng Zhang ; Zhigang Guo ; Dongyuan Zhao
• 关键词：Mesoporous anatase TiO2&ndash ; SiO2 nanocomposites ; Excellent photocatalytic degradation activities ; Cationic dyes ; Anionic dyes ; Microcystin-LR
• 刊名：Journal of Hazardous Materials
• 出版年：2012
• 出版时间：30 August, 2012
• 年：2012
• 卷：229-230
• 期：Complete
• 页码：307-320
• 全文大小：1455 K

文摘

Ordered 2-D hexagonal mesoporous TiO₂-SiO₂ nanocomposites consisted of anatase TiO₂ nanocrystals and amorphous SiO₂ nanoparticles, with large mesochannels and high specific surface areas, have been extensively and detailedly evaluated using various cationic dyes (methylene blue, safranin O, crystal violet, brilliant green, basic fuchsin and rhodamine-6G), anionic dyes (acid fuchsin, orange II, reactive brilliant red X3B and acid red 1) and microcystin-LR. We use mesoporous 80TiO₂-20SiO₂-900 for the degradation of cationic dyes and MC-LR, due to the dominant adsorption of SiOH groups and synergistic role of coupled adsorption and photocatalytic oxidation. For anionic dyes, due to the adsorption results predominantly from TiOH groups, our strategy realizes the enhanced photocatalytic oxidation by strong surface acids and larger available specific surface area. Based on this, we prepared 90TiO₂-10SiO₂-700 to degrade them. The results show that our samples exhibit excellent degradation activities to all the contaminants, which are much higher than that of P25 photocatalyst. The dyes are not only decolorized promptly but degraded readily as well. It is strongly indicated that our mesoporous nanocomposites are considerably stable and reusable. These results demonstrate that our mesoporous TiO₂-SiO₂ nanocomposites present extensive and promising application in the fast and highly efficient degradation of various organic pollutants.