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

Abstract

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 electron–hole pairs. The fabrication of mesoporous TiO₂ composites, especially heterojunctions, could make full use of the characteristics of each component for improving the overall 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.