TiO ₂ photoelectrode generated by titanium anodization on FTO conductive glass for the degradation of persistent pollutants in aqueous media

Abstract A TiO 2 photoelectrode generated by anodization of Ti films deposited on fluorine-doped tin oxide (FTO) as substrate by vapor phase deposition method in an ultra-high vacuum (UHV) has been developed for photocatalytic, electrochemical, and photoelectrochemical degradation of pollutants. In the deposition process, plates with an average thickness of 0.40 µm of Ti were obtained. These plates were anodized at 3.0 V in an electrolytic solution of ethylene glycol/water and heat-treated at 450 °C for 2 hours. Subsequently, the plates were characterized by SEM, AFM, and XRD, which revealed nanoporous TiO 2 structures with a high percentage of crystallization with the rutile phase. The FTO–TiO 2 plates were shown to be effective in the degradation of methylene blue and the herbicide terbutryn. The photoelectrochemical process resulted in the highest degradation percentages, with degradations above 80 % of methylene blue (1.5 × 10 −5 mol L −1 ) and terbutryn (6.14 × 10 −6 mol L −1 ) in 2 hours.