Enhanced Photocatalytic Ozonation Using Modified TiO 2 With Designed Nucleophilic and Electrophilic Sites.

Photocatalytic ozonation is considered to be a promising approach for the treatment of refractory organic pollutants, but the design of efficient catalyst remains a challenge. Surface modification provides a potential strategy to improve the activity of photocatalytic ozonation. In this work, density functional theory (DFT) calculations were first performed to check the interaction between O 3 and TiO 2 -OH (surface hydroxylated TiO 2 ) or TiO 2 -F (surface fluorinated TiO 2 ), and the results suggest that TiO 2 -OH displays better O 3 adsorption and activation than does TiO 2 -F, which is confirmed by experimental results. The surface hydroxyl groups greatly promote the O 3 activation, which is beneficial for the generation of reactive oxygen species (ROS). Importantly, TiO 2 -OH displays better performance towards pollutants (such as berberine hydrochloride) removal than does TiO 2 -F and most reported ozonation photocatalysts. The total organic carbon (TOC) removal efficiency reaches 84.4 % within two hours. This work highlights the effect of surface hydroxylation on photocatalytic ozonation and provides ideas for the design of efficient photocatalytic ozonation catalysts.