Visible light-induced catalytic degradation of iprobenfos fungicide by poly(3-octylthiophene-2,5-diyl) film

Abstract

Visible light-induced catalytic degradation of iprobenfos fungicide was investigated using poly(3-octylthiophene-2,5-diyl) (POTh) film by varying oxygen pressure of bubbling gases. The degradation rate increased with the increasing oxygen pressure and obeyed a first-order kinetics in bubbling air. Even after 10 h irradiation ( λ>380 nm), the film was substantially stable and no peeling was observed. The quenching of photoluminescence of POTh with O 2 was observed and the formation of active oxygen species such as H 2O 2 and OH was detected spectrophotometrically. An OH adduct of iprobenfos as well as decomposed intermediates and SO 4 2− was also confirmed. The addition of Fe 2+ accelerated the photocatalytic degradation of iprobenfos by the POTh film. Based on these results, a photocatalytic degradation mechanism is proposed.