Photoelectrocatalytic degradation of benzoic acid using immobilized tungsten trioxide photocatalyst

The thin films of WO3 were deposited with different solution quantities using chemical spray pyrolysis technique. The WO3 film thickness effect on the photoelectrochemical, structural, morphological and optical properties is studied. Polycrystalline, monoclinic WO3 films possess photoelectrochemical performance having onset potentials around +0.3 V/SCE in 0.01 M HClO4. The maximum photocurrent density (Iph = 635 μA/cm2) is observed for the film deposited with 75 ml solution quantity. The FE-SEM image shows compact structure with petals like morphology. The estimated indirect band gap of WO3 films lies in the range of 2.60-2.65 eV. The photoelectrocatalytic degradation of benzoic acid is studied using WO3 photoelectrode under UV light illumination and 57 ± 3% removal of benzoic acid is achieved. The mineralization of benzoic acid in aqueous solution has been studied by measuring COD values.