Growth and Optical Properties of Flux-Synthesized Decahedral Anatase TiO<sub>2</sub>

Decahedral anatase TiO2 particles with exposed (101) and (001) planes were successfully grown in LiCl–KCl molten salts under HF-free conditions. The particle size was adjusted to ∼30 or ∼700 nm by tuning annealing temperature, molten salt composition, and annealing time. These particles exhibited UV light absorption based on electron excitation from the valence band to the conduction band, and scattering in the UV–visible range based on Mie resonance. The latter strongly depended on the TiO2 particle size. The optical near-field distributions under circularly polarized light were also size-dependent.