Metal oxide based nanomaterials for drugs photodegradation

Abstract

Nowadays, dealing with water pollution caused by pharmaceutical compounds has become a major problem worldwide. Year after year the concentration of antibiotics, both in surface and ground water, is increasing. Several techniques are being employed on trying to solve this issue. Among them, heterogeneous photocatalysis, including advanced oxidation processes (AOPs), is known to be very effective in degrading a wide spectrum of organic pollutants, ranging from pesticides to antibiotics. In this thesis, an attempt was made to combine effective well known photocatalysts like titanium dioxide and tungsten trioxide with iron oxide-based nanostructures, aiming to enhance the efficiency of degradation, while compensating the drawbacks of these materials. In detail, Fe2O3 nanorings structures were coated, combining hydro-thermal and sonication approaches, with TiO2, WO3 and both TiO2/WO3 to obtain different core-shell systems. In order to obtain core-related magnetic properties, for an easy recovery of the samples from treated water, some tests were performed, via microwave hydro-thermal treatments, to obtain maghemite nanorings starting from hematite cores. Several techniques were used to characterize the obtained samples: SEM for the morphological studies, XRD and EDX to determine their compositions and crystalline phases and UV-Vis spectroscopy to investigate their optical properties. Finally, the photoactivity of the obtained systems was investigated through photodegradation reactions at room temperature and atmospheric pressure, under both UV and simulated solar light irradiation, in an aqueous solution containing Metronidazole (MDZ) as a well-known pollutant and probe molecule.