Theoretical study on degradation mechanism of ornidazole on anatase TiO2 (101) and (001) surfaces
Ornidazole (ONZ) residue is an emerging pollutant posing a huge threat to environment and human. In this paper, the degradation mechanism of ONZ on anatase TiO2 (101) and (001) surfaces in vacuum and neutral aqueous solution were elucidated at DFT level. We found that ONZ was activated and oxidized after being adsorbed on the surface of TiO2, the C-N bond became longer, making the ring-opening degradation more likely to occur. This study found that the degradation of ONZ is more probable on the surface of TiO2(001) than that on TiO2(101). When the reaction changes from the vacuum to aqueous solution, the activation energy of ONZ degradation reaction on TiO2 surfaces was significantly decreased, which indicated that the solvent condition was more favorable for ONZ degradation.