Anionic and cationic dyes removal by degradation via photoelectrocatalysis using a WO3/CuWO4 heterojunction film as a photoanode

Abstract

Population growth increases the disposal of organic pollutants in aqueous environments, including anionic and cationic dyes. Tungsten trioxide (WO3) and copper tungstate (CuWO4) have been considered as photocatalysts for the degradation of these pollutants by photoelectrocatalysis. However, these semiconductors used individually have some properties that reduce their potential for application in photoelectrocatalysis. Thus, this work proposed the in-situ synthesis of a WO3/CuWO4 heterojunction film for photoelectrocatalysis of anionic and cationic dyes. The structural characterization showed the monoclinic and triclinic phases in the nanocomposite corresponding to WO3 and CuWO4, respectively. The optical characterization revealed a better visible light absorption for the heterojunction film. The film formed nanoplates grown perpendicular on the conductive substrate, which can mitigate the charge recombination process. The photoelectrochemical characterizations showed superior photoelectrochemical stability for the WO3/CuWO4 film and the best activity to remove cationic dyes.