Stannic Oxide-Titanium Dioxide Coupled Semiconductor Photocatalyst Loaded with Polyaniline for Enhanced Photocatalytic Oxidation of 1-Octene

Stannic oxide-titanium dioxide (SnO2–TiO2) 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 ofSnO2and followed by attachment of PANI onto aTiO2powder to give sample PANI-SnO2–TiO2. The electrical conductivity of the system becomes high in the presence of PANI. Enhanced photocatalytic activity was observed in the case of PANI-SnO2–TiO2compared to PANI-TiO2,SnO2–TiO2, andTiO2. A higher photocatalytic activity in the oxidation of 1-octene on PANI-SnO2–TiO2thanSnO2–TiO2, PANI-TiO2, andTiO2can be considered as an evidence of enhanced charge separation of PANI-SnO2–TiO2photocatalyst as confirmed by photoluminescence spectroscopy. It suggests that photoinjected electrons are tunneled fromTiO2toSnO2and then to PANI in order to allow wider separation of excited carriers.