Effect of operational parameters on decolorization of Acid Yellow 23 from wastewater by UV irradiation using ZnO and ZnO/SnO2 photocatalysts

► ZnO/SnO2 coupling is used in the decolorization of dyes in combination with UV light. ► The photocatalytic activity of ZnO and SnO2 is effectively enhanced by coupling catalysts ► Changing the ratio of coupled ZnO/SnO2 affects the photocataytic activity.