A highly efficient visible-light responsive sprayed WO 3 /FTO photoanode for photoelectrocatalytic degradation of brilliant blue

Abstract In present article, WO 3  thin films have been successfully synthesized by chemical spray pyrolysis approach. The effect of spraying quantity of solution onto the photoelectrochemical (PEC), structural, morphological, and optical properties has been studied. Film prepared at 40 ml solution quantity shows the excellent photoelectrochemical performance ( I sc = 0.69 mA/cm 2 and V oc  = 0.64 V) in 0.05 M concentrated H 2 SO 4 electrolyte. X-ray diffraction studies reveal that the synthesized WO 3  thin films are polycrystalline with monoclinic crystal structure. The chief vibrational modes of the WO 3 sample, located at 712.64 and 804.28 cm −1  corresponding to the stretching and the bending of O W O bond respectively and are consistent with a monoclinic structure. The estimated band gap energy of WO 3  thin films varies from 2.37 to 2.45 eV with respect to quantities of spraying solution and it exhibits absorption in visible region. Film shows a maximum specific surface area of 31.63 m 2 /g. Photoelectrocatalytic degradation of brilliant blue dye in aqueous solutions is studied. The end result shows that the degradation percentage of brilliant blue using WO 3  photoelectrode has reached 92% under visible light illumination after 240 min. The enhancement in photoelectrocatalytic activity of optimized 40 ml WO 3 sample is mainly due to the suppressed the recombination rate of photogenerated electron–hole pairs. This study provides an effective WO 3 photoelectrode for removing of organic pollutants present in the water.