Sunlight assisted novel spray deposited Bi2WO6 photoelectrode for degradation of organic pollutants

• Published in: The Journal of physics and chemistry of solids 2022-09, Vol.168, p.110786, Article 110786
• Main Authors: Suryavanshi, R.D., Babar, P.V., Narewadikar, N.A., Rajpure, K.Y.
• Format: Article
• Language: English
• Subjects: Benzoic acid and Methyl blue dye; Bi2WO6 thin films; Photocatalysis; Spray pyrolysis
• ISSN: 0022-3697; 1879-2553
• DOI: 10.1016/j.jpcs.2022.110786

The present investigation reports on the degradation of benzoic acid (BA) and methyl blue (MB) dye using spray deposited (area 64 cm2) Bi2WO6 photoelectrode. The experimental result shows high degradation efficiency in the photoelectrocatalytic method than in photocatalysis. Around 72 and 98 % degradation of BA and MB dye was observed in 400 and 160 min respectively with the help of Bi2WO6 photoelectrode. All the deposited Bi2WO6 films are polycrystalline with rhombohedral crystal structures as revealed from the XRD study. The maximum PEC response of the film was observed at 1.20 μm thickness [short circuit current (Isc = 0.437 mA) and open-circuit voltage (Voc = 452 mV)]. The morphological study shows, closed packed with a high porous granular structure on the surface of the deposited film and its size increases concerning the thickness of the film. The estimated bandgap energy of Bi2WO6 films varied from 2.74 to 2.78 eV. The flat band study of Bi2WO6 film shows −0.43 V/NHE. Finally, the mineralization of pollutants is studied by measuring chemical oxygen demand (COD) values. Therefore, it concludes that Bi2WO6 good candidate for the degradation of BA and MB dye from wastewater. [Display omitted] •Bi2WO6 thin films have been successfully synthesized by a simple chemical spray pyrolysis technique.•The effect of thickness variation on the photoelectrochemical, structural, morphological and optical properties has been studied.•Film prepared at 1.20 μm thickness shows the maximum PEC response in 0.01 M NaOH electrolyte.•The flat band potential of the optimized Bi2WO6 thin film is −0.43V/NHE.•Finally, study the degradation of benzoic acid and methyl blue dye using a large area (64 cm2) Bi2WO6 photoelectrode under solar light illumination.