Enhanced Photocatalytic Ozonation Using Modified TiO 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 and TiO-OH (surface hydroxylated TiO) or TiO-F (surface fluorinated TiO), and the results suggest that TiO-OH displays better O adsorption and activation than does TiO-F, which is confirmed by experimental results. The surface hydroxyl groups greatly promote the O activation, which is beneficial for the generation of reactive oxygen species (ROS). Importantly, TiO-OH displays better performance towards pollutants (such as berberine hydrochloride) removal than does TiO-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.