Hydrothermal Synthesis of Titanium Oxide

A certain amount of 1-butanol diluted titanium butoxide and hydrofluoric acid (48.0 wt.%) were mixed with a Ti/F of 4:1. The mixture was added to a 50 mL Teflon-lined stainless-steel autoclave after being stirred for 1 h at room temperature and kept at 160 °C for 24 h. After the reaction, the white precipitates were separated through centrifugation, and the supernatant was transferred to another Teflon-lined stainless-steel autoclave and kept at 210 °C for 60 h. The resulting light blue precipitate was washed multiple times by pure ethanol, pure acetone, and water, and sonicated for 1 day. Finally, the sample were dried in vacuum at ambient temperature for 1 day.