Photodegradation of diethyl phthalate with PANi/CNT/TiO2 immobilized on glass plate irradiated with visible light and simulated sunlight-effect of synthesized method and pH.

Diethyl phthalate (DEP) is one of the most common phthalates for industrial use and has widely spread in environment. A series of PANi/CNT/TiO2 potocatalysts immobilized on glass plate irradiated with visible light were presented to degrade DEP in this study. The PANi/CNT/TiO2 potocatalysts were fabricated by co-doping with polyaniline (PANi) and two functionalized CNT (CNT-COCl and CNT-COOH) onto TiO2 followed by a hydrothermal synthesis and a sol-gel hydrolysis. Doping of PANi resulted in the absorption edge of the fabricated potocatalysts shifting to 421-437nm and the most distinguished red-shift effect was found in hydrothermal synthesized photocatalysts. The best DEP degradation of 41.5-59.0% and 44.5-67.4% was found in the simulated sunlight system irradiated for 120min for sol-gel hydrolysis PANi/CNT/TiO2 photocatalysts and hydrothermal synthesized ones, respectively. The optimum pH was determined at 5.0 and 7.0 for the two PANi/CNT/TiO2 photocatalysts mentioned above, respectively. The reusability of the sol-gel hydrolyzed photocatalysts up to 5 times was observed no decline in the photodegradation efficiency but less photocatalytic stability of the hydrothermal synthesized ones was found. Meanwhile, the active species of OH radicals generated in the DEP degradation system was identified by free radical scavenging experiments.