Self-assembly and photocatalysis of mesoporous TiO2 nanocrystal clusters
Self-assembly and photocatalysis of mesoporous TiO2 nanocrystal clusters
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DOI：
10.1007/s12274-010-0058-9
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发表时间：
2011
期刊：
影响因子：
9.9
通讯作者：
Qiao Zhang;J. Joo;Zhenda Lu;Michael Dahl;D. L. Oliveira;Miaomiao Ye;Yadong Yin
中科院分区：
文献类型：
--
作者：
Qiao Zhang;J. Joo;Zhenda Lu;Michael Dahl;D. L. Oliveira;Miaomiao Ye;Yadong Yin
成功合成了具有大比表面积和高光催化活性的介孔纳米TiO 2团簇。该合成涉及到疏水二氧化钛纳米晶体的自组装成亚微米簇，这些簇与二氧化硅层的涂层，热处理，以消除有机配体和提高集群的结晶度，最后除去二氧化硅暴露的介孔催化剂。在二氧化硅涂层的帮助下，团簇不仅保持其小的晶粒尺寸，而且在高温煅烧后保持其介孔结构（BET表面积高达277 m2/g）。SiO2的刻蚀也导致团簇在水中具有高分散性。我们已经能够确定最佳的煅烧温度，以产生具有高结晶度和大的表面积的TiO 2纳米团簇，因此在紫外光照射下的有机分子的分解中显示出优异的催化效率。方便的氮掺杂将这些双金属簇转化为可见光和自然阳光下的活性光催化剂。利用纳米晶体形成明确的介孔簇的策略有望为设计具有增强的活性和稳定性的光催化剂提供一种通用和有用的方法。
Mesoporous nanocrystal clusters of anatase TiO2with large surface area and enhanced photocatalytic activity have been successfully synthesized. The synthesis involves the self-assembly of hydrophobic TiO2nanocrystals into submicron clusters, coating of these clusters with a silica layer, thermal treatment to remove organic ligands and improve the crystallinity of the clusters, and finally removing silica to expose the mesoporous catalysts. With the help of the silica coating, the clusters not only maintain their small grain size but also keep their mesoporous structure after calcination at high temperatures (with BET surface area as high as 277 m2/g). The etching of SiO2also results in the clusters having high dispersity in water. We have been able to identify the optimal calcination temperature to produce TiO2nanocrystal clusters that possess both high crystallinity and large surface area, and therefore show excellent catalytic efficiency in the decomposition of organic molecules under illumination by UV light. Convenient doping with nitrogen converts these nanocrystal clusters into active photocatalysts in both visible light and natural sunlight. The strategy of forming well-defined mesoporous clusters using nanocrystals promises a versatile and useful method for designing photocatalysts with enhanced activity and stability.