Photodegradation of selected pesticides: Photocatalytic activity of bare and PANI-modified TiO2 under simulated solar irradiation

Abstract

In this paper the efficiency of photocatalytic degradation of different pesticides was investigated using bare TiO2 and TiO2 nanoparticles modified with polyaniline under simulated solar irradiation. Sulcotrione showed the highest percentage degradation and further experiments were related to this herbicide. Mineralization and cytotoxicity of the starting compound and intermediate species formed during the decomposition in double distilled water (DDW), as well as the efficiency of removal from various environmental waters were studied. The contents of the most abundant ions present in the River Danube were simulated in DDW and their influence was evaluated. It was found that cytotoxicity was in all cases below 11 % and the efficiency of photocatalytic degradation in environmental waters was decreased compared with DDW. Furthermore, addition of different scavengers revealed that the main path of degradation is through holes, while the presence of H2O2 decreased and KBrO3 increased the efficiency of photocatalytic degradation compared with the system without the mentioned electron acceptors.