Hydrothermal synthesis of Rb and S co-doped Ti-based TiO sheet with a thin film showing high photocatalytic activities.

TiO is considered as one of the most promising semiconductor photocatalysts used to degrade organic pollutants. Element doping has a good effect on improving the properties of TiO. Herein, by using RbSO, we explored the synthesis of Ti-based TiO sheets with a thin film through a hydrothermal reaction. Then, the photocatalyst was successfully fabricated by calcination. All samples were characterized by FT-IR, XRD, SEM, XPS, PL and UV-vis DRS measurements. The results indicate that the S doping together with surface hydroxyl groups lead to the band gap narrowing. S and a trace amount of Rb element can enable the formation of uniform microspheres on the surface of the Ti plate and the major phase transformed from titanium to anatase. The band gap absorption extended from 400 nm to 600 nm. The photocatalytic properties were investigated by performing the degradation of methyl orange (MO) and 4-chlorophenol (4-CP) in the aqueous solutions under UV and simulated sunlight. In the series of TiO photocatalysts, Rb/S/TiO-48 shows the best photocatalytic efficiency and good photocatalytic performance on recycling. Interestingly, when HO was added to the MO aqueous solution, a synergistic effect of the TiO thin film and HO on degrading the pollutant was observed.