Photoactivity of TiO2 nanoparticles covered with nitro group in Fluoxetine and Rhodamine-B degradation

TiO2 nanoparticles and TiO2 covered with nitro groups were prepared. Nanoparticles with diameters of 15-25 nm were obtained, consisting 100% of the anatase phase (for heat treatment of 450 degrees C) and some peaks referring to the rutile phase (for heat treatment of 500 degrees C). The X-ray diffraction and Raman spectroscopy analysis showed crystalline structure without deformations, indicating that the nitro groups present on the surface did not influence these properties. Infrared spectra showed the presence of nitro groups on the surface of the semiconductor (450TiN12), which resulted in degradation of 70% compared to photolysis when applied in the Rhodamine B photo-degradation. The semiconductors were then applied in the fluoxetine (FLX) degradation. The pH monitoring showed that TiO2 covered with nitro groups, and treated at 450 degrees C for 12 h, resulted in increased deprotonation (above 100%) when compared to the process using pure TiO2. The studies permitted defining the behavior of the FLX degradation and the understanding of the mechanism resulting from the insertion of TiO2 covered with nitro groups (electrophiles), which interact with the FLX (nucleophile) amino group promoting its deprotonation. These results can be used in the design of new materials to be applied in pharmaceutical photodegradation.