Photoelectrocatalytic degradation of benzoic acid using immobilized tungsten trioxide photocatalyst

Abstract The thin films of WO 3 were deposited with different solution quantities using chemical spray pyrolysis technique. The WO 3 film thickness effect on the photoelectrochemical, structural, morphological and optical properties is studied. Polycrystalline, monoclinic WO 3 films possess photoelectrochemical performance having onset potentials around +0.3 V/SCE in 0.01 M HClO 4 . The maximum photocurrent density (I ph  = 635 μA/cm 2 ) 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 WO 3 films lies in the range of 2.60–2.65 eV. The photoelectrocatalytic degradation of benzoic acid is studied using WO 3 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.