Mesoporous Structure with Size Controllable Anatase Attached on Silicate Layers for Efficient Photocatalysis

A new composite structure with superior photocatalytic activity for phenol decomposition was prepared by reaction between TiOSO 4 and a synthetic layered clay laponite. The high photocatalytic activity resulted from the unique structure of the composite, in which anatase nanocrystals were attached on leached laponite fragments. The new materials are distinctly different from the conventional TiO 2 -pillared clays in structure, which are microporous solids with small TiO 2 particles (a few nanometers in size) as pillars. The large number of the anatase crystals (the active sites) and better accessibility to the sites by UV light and reactant molecules are the major factors enhancing the photocatalytic activity. Important structural properties of the porous composites, such as specific surface area, pore structure, and size of the anatase crystals, were tailored by modulating the Ti/clay ratio and the hydrothermal synthesis temperatures. The performance of the catalysts is related to their structural features, and it is found that the catalytic activity increased with increasing size of the anatase crystals in the catalysts, specific surface area, and mesopore size.