Radial TiO2 Nanorod-Based Mesocrystals: Synthesis, Characterization, and Applications

Abstract

Radial TiO2 nanorod-based mesocrystals (TiO2-NR MCs) or so-called “sea-urchin-like microspheres” possess not only attractive appearance but also excellent potential as photocatalyst and electrode materials. As a new type of TiO2-NR MCs, we have recently developed a radial heteromesocrystal photocatalyst consisting of SnO2(head) and rutile TiO2 nanorods(tail) (TiO2-NR//SnO2 HEMCs, symbol “//” denotes heteroepitaxial junction) with the SnO2 head oriented in the central direction in a series of the studies on the nanohybrid photocatalysts with atomically commensurate junctions. This review article reports the fundamentals of TiO2-NR MCs and the applications to photocatalysts and electrodes. Firstly, the synthesis and characterization of TiO2-NR//SnO2 HEMCs is described. Secondly, the photocatalytic activity of recent TiO2-NR MCs and the photocatalytic action mechanism are discussed. Thirdly, the applications of TiO2-NR MCs and the analogs to the electrodes of solar cells and lithium-ion batteries are considered. Finally, we summarize the conclusions with the possible future subjects.