Hexafluorotitanic acid-assisted synthesis of large-sized, ultrathin titania nanosheets as multifunctional and high-performance photocatalysts

Abstract A fast cyclohexanol solvothermal pathway was developed to prepare highly dispersed anatase titania (TiO 2 ) nanosheets with an edge length of ∼800 nm and a thickness of ∼6 nm. Under the synergistic control of hexafluorotitanic acid and cyclohexanol, the exposed 001 facets reached ∼98.5% on the TiO 2 nanosheets obtained by the treatment at 180 °C for 150 min. Moreover, it was found that the phase transformation and structural development drastically occurred during the solvothermal treatment. When used as a catalyst for photodegradation of rhodamine B, the TiO 2 nanosheets exhibited a good recycling stability and a much higher photocatalytic degradation rate (nearly 99% degradation within 2.5 h) than the commercial P25 (93.6%). After being uniformly loaded with 4 wt.% of the Pt nanoparticles, the TiO 2 nanosheets displayed a photocatalytic hydrogen production rate of 2.239 mmol g −1 h −1 under simulated solar light, which was much higher than the pristine TiO 2 nanosheets (0.045 mmol g −1 h −1 ) as well as most of the reported TiO 2 -based photocatalysts. The remarkable photocatalytic activity and good stability of the TiO 2 nanosheets with highly exposed 001 facets would make them find potential applications in both water treatment and hydrogen generation from water splitting under solar light.