Construction of TiO2 Hierarchical Nanostructures from Nanocrystals and Their Photocatalytic Properties

Anatase TiO2 mesoporous structures with high specific surface areas are of special significance in various applications. In this work, hierarchical anatase TiO2 materials with flowerlike morphologies have been prepared via a one-step template-free hydrothermal method, by using titanocene dichloride as precursor and EDA as chelating agent in aqueous solution. Particularly, the hierarchical structures are assembled from very thin TiO2 nanosheets, which are composed of numerous highly crystallized anatase nanocrystals. In addition, the assembled materials own relatively large specific surface areas of 170 m2/g, and uniform mesopores of 7 nm. We further demonstrate that the hierarchical TiO2 materials show very good photocatalytic performance when applied in photodegradation of methylene blue, which should be related to the unique features of hierarchical structures, large specific surface areas and high crystallization degree of the obtained TiO2 materials. With these features, the hierarchical TiO2 may find more potential applications in the fields such as dye-sensitized solar cells and lithium ion batteries.