TiO2 mesocrystals: recent progress in synthesis, structure, and photocatalytic applications

Abstract Nanomaterials are distinct from conventional bulk crystals due to their unique characteristics, which include surface morphology, size distribution, crystallinity, specific surface area, and electrical and thermal conductivities. An ordered collection of these nanocrystals, known as Mesocrystals, exhibits a superstructure order that gives rise to collective and emergent properties. Among the various mesocrystals, titanium dioxide mesocrystals are particularly noteworthy because of their potential applications as exceptional photocatalysts and electrodes. Their unique features, such as anisotropic shape, mesocrystal porosity, nanoscale size, mechanical stability, and optoelectronic properties, make them a research focus. This review provides an overview of new synthetic strategies for titanium dioxide mesocrystals and their hybrid composite materials published after 2020. It thoroughly explains the latest advancements in synthetic methods, mechanisms of formation, surface structures, defect states, and environmental applications, especially the robotic form of single and multicomponent TiO2-based mesocrystals in environmental and miscellaneous applications. Furthermore, this review sheds light on future possibilities of static and robotic TiO2-based mesocrystals.