Photoelectrochemical degradation of pharmaceuticals at β25 modified WO3 interfaces

In this contribution we have explored the applications of WO3 based nanomaterials to the degradation of Ketoprofen and Levofloxacin, selected among the most widely used anti-inflammatory and analgesic species and antibiotics and representing thus ubiquitous water contaminants of emerging concern. Compared to conventional photocatalytic conditions, which were not effective in the oxidative degradation of Ketoprofen, the application of the electric bias was successful in promoting a 50% Ketoprofen degradation after 5 h illumination, with a degradation rate constant of 0.22 h−1. A similar improvement was found with Levofloxacin. The degradation rate was further accelerated by exploiting WO3 films modified with β25 zeolites which achieved, on the same time scale, >65% degradation with Ketoprofen and ca. 90% with Levofloxacin. The complete disappearance of the oxidation intermediates of these two drugs was observed on a time scale of ca. 20 h, indicative of the achievement of complete drug mineralization at the illuminated β25/WO3 interface under 1 sun illumination.