Green synthesis of TiO2nanocrystals with improved photocatalytic activity by ionic-liquid assisted hydrothermal method

Abstract

Owing to potential industrial applications and fundamental significance, tailored synthesis of well-defined anatase TiO₂ nanocrystals with exposed highly reactive {001} facets has stimulated great research interest. In this work, surface-fluorinated anatase TiO₂ nanocrystals have been successfully prepared by using an ionic liquid (IL) assisted hydrothermal synthetic route. TiCl₄ is used as precursor, and 1-butyl-3-methylimidazolium tetrafluoroborate ([Bmim]⁺[BF₄]⁻) as morphology-controlling agent. The anion of the IL plays a key role in controlling the crystallization process via a dissolution–recrystallization process. Compared with the benchmark material Degussa P25, the fluorinated anatase TiO₂ nanocrystals exhibit superior photocatalytic activity.