Efect of Ti F surface interaction on the photocatalytic degradation of phenol, aniline and formic acid

A study is undertaken of the effect of fluorinating two TiO catalysts, both with the same surface area but one composed only of pure anatase phase (SA) and the other of mixed anatase and rutile phases (P25), on the degradation of phenol, formic acid and aniline. The catalysts were characterised by FTIR, BET, EDAXs, SEM, XRD and DRS-UV–vis studies. The method used for synthesis of the F-P25 and F-SA resulted in fluorinated catalysts with properties different to those of other fluorinated catalysts reported in the bibliography. The results obtained show that, unlike other studies in which the formation of free hydroxyl radicals ([rad]OH) was enhanced with the fluorinated catalysts, in the F-P25 and F-SA catalysts it was the formation of surface hydroxyl radicals ([rad]OH) which was significantly enhanced. In this way, the F-P25 and F-SA catalysts gave rise to higher degradation rate constants of phenol (k), aniline (k) and formic acid (k) than the P25 and SA catalysts.
We are grateful for the financial support of the Spanish Ministry of Economy and Competitiveness through the projects CTQ2015-64664-C2-1-P and the Spanish Ministry of Science and Innovation for the UNLP10-3E-726 infrastructure, co-financed with ERDF funds. D. Garzón Sousa would like to thank the University of La Palmas de Gran Canaria for its funding through its PhD Grant Program and Wiâm El-Alami would also like to thank the UNetBA Erasmus Program for its funding through a mobility grant.