Mesoporous TiO2: Preparation, Doping, and as a Composite for Photocatalysis

Mesoporous materials are widely used in solar cells, lithium-ion batteries, sensors, and supercapacitors. Mesoporous TiO2 is also highly active in photocatalysis, owing to the benefits of the mesoporous network in promoting the diffusion of the reactants and products, as well as in facilitating access to the reactive sites on the surface of the photocatalysts. This Minireview focuses on the development of mesoporous TiO2, metal/nonmetal-doped mesoporous TiO2 networks, and mesoporous TiO2 composites. The design and synthesis of mesoporous TiO2, including the formation of various mesostructured frameworks, pore-size control, large-pore-size fabrication, and highly thermally stable mesoporous-network formation, are described in detail. From an application viewpoint, the subsequent fabrication of doped and multifunctional heterojunctions in mesoporous TiO2 is necessary for further improving its photocatalytic performance. The doping of mesoporous TiO2 with metals or nonmetals could extend the absorption edge into the visible-light spectrum and improve the separation efficiency of photogenerated electronhole pairs. The fabrication of mesoporous TiO2 composites, especially heterojunctions, could make full use of the characteristics of each component for improving the ov(e)rall photocatalytic performance. In view of this fact, mesoporous TiO2 still possesses significant room for development in photocatalysis and is worthy of greater attention in the future.