Photocatalytic degradation of benzene in gas phaseby nanostructured BiPO4 catalysts

A rod-shaped BiPO4 photocatalyst was prepared by a simple hydrothermal method forlight-induced catalytic degradation of stable aromatic compounds such as benzene in gas phaseunder ambient conditions. The samples were subjected to various technical characterizationsincluding X-ray diffraction (XRD), transmission electron microscopy (TEM), UV/vis and FTIRspectrum, to determine the crystal structure, morphology, and optical properties of the as-preparedphotocatalysts. Results indicate that BiPO4 exhibits much higher photocatalytic activity andstability under UV light irradiation than that of commercial TiO2 (Degussa P25) in the degradationof benzene to CO2. The active radical species involved in the degradation reactions over BiPO4photocatalyst have been investigated by the spin-trapping electron paramagnetic resonance (EPR)spectra and a photoluminescence technique. Theoretical calculations reveal that BiPO4 containshighly-dispersive conduction bands, enabling high mobility of the photo-generated carries andtherefore leading to fast charge transfer and separation.