Photocatalytic degradation of pharmaceuticals in waterDesign of nanocatalysts and study of by-products and mechanism stars

Abstract

This PhD thesis pursues the photocatalytic degradation of different pharmaceuticals (paracetamol, ibuprofen, diclofenac, naproxen and ciprofloxacin) in water. For this purpose different photocatalysts were synthesised and characterised. Moreover, the photocatalytic performance of TiO2 and g-C3N4 was tuned by grafting nanoparticles and creating unions between semiconductors to tailor the band gaps of the photocatalysts. In some cases, the effect of pH in the degradations was assessed and the stability of g-C3N4 in some degradations was studied. Furthermore, the mechanism of degradation was studied introducing different scavengers in the degradations in order to identify which active species played a main role in the degradations. The by-products generated were also identified by high resolution mass spectrometry. And different set-ups (different water matrixes, different sources of irradiation, different catalytic systems...) were studied. The noble metal nanoparticles enhanced the photocatalyst performance avoiding fast electron-hole pair recombination and thank to their plasmonic properties. All degradations followed kinetics of pseudo-first-order.