Stannic oxide-titanium dioxide coupled semiconductor photocatalyst loaded with polyaniline for enhanced photocatalytic oxidation of 1-octene

Abstract

Stannic oxide-titanium dioxide ( SnO 2 TiO 2) coupled semiconductor photocatalyst loaded with polyaniline (PANI), a conducting polymer, possesses a high photocatalytic activity in oxidation of 1-octene to 1,2-epoxyoctane with aqueous hydrogen peroxide. The photocatalyst was prepared by impregnation of SnO 2 and followed by attachment of PANI onto a TiO 2 powder to give sample PANI- SnO 2 TiO 2 . The electrical conductivity of the system becomes high in the presence of PANI. Enhanced photocatalytic activity was observed in the case of PANI- SnO 2 TiO 2 compared to PANI- TiO 2, SnO 2 TiO 2, and TiO 2 . A higher photocatalytic activity in the oxidation of 1-octene on PANI- SnO 2 TiO 2 than SnO 2 TiO 2, PANI- TiO 2, and TiO 2 can be considered as an evidence of enhanced charge separation of PANI- SnO 2 TiO 2 photocatalyst as confirmed by photoluminescence spectroscopy. It suggests that photoinjected electrons are tunneled from TiO 2 to SnO 2 and then to PANI in order to allow wider separation of excited carriers.