Photodegradation of Naproxen Using Ag/AgCl–PANI Composite under Solar Light: Transformation Products and Reaction Kinetics
The photocatalytic degradation of organic micropollutant naproxen (NPX) was evaluated under solar light using Ag/AgCl–polyaniline (Ag/AgCl–PANI) photocatalyst. The degradation experiments were monitored using ultra-performance liquid chromatography (UPLC) coupled with electrospray ionization and tandem mass spectrometry. High stability and high photocatalytic degradation rate of NPX were observed with a first-order kinetics behavior. The degradation rate increases with increasing photocatalyst dose and decreases with increasing initial NPX concentration of NPX. Besides, the highest photocatalytic activity of Ag/AgCl–PANI(5%) towards the removal of NPX was in basic media (pH 11). However, the complete mineralization of NPX needed more time than that of its photodegradation indicating the presence of NPX derived byproduct. The transformation products were identified by gas chromatography-mass spectrometry. h+ and O2, the oxidizing species, exhibit an electron transfer oxidation process and result in two different reaction pathways.