Application of WO3 and Zn-doped WO3 prepared by microwave irradiation for photocatalytic degradation of Rhodamine B in water and wastewater

Abstract

This research focused on the structural, optical, and electrochemical characterization of WO3 and Zn-doped WO3, as well as their application as photocatalysts for the degradation of Rhodamine B (RhB), a growing organic contaminant from water and wastewater, when exposed to visible light. According to structural analyses, microwave irradiation successfully generated nanorod-shaped WO3 and Zn-doped WO3 structures. The optical band gap values of WO3 and Zn-doped WO3 structures were determined to be 3.12 and 2.83 eV, respectively, resulting in quick charge transfer and leading to an increase in the photocatalytic activity of the Zn-doped WO3 structure under visible light irradiation. According to electrochemical experiments, the lifespan of photo-generated electrons in Zn-doped WO3 was longer than that of WO3, indicating that Zn-doped WO3 had the highest separation efficiency and the fastest diffusion rate. The entire degradation efficiency of 150 mL of 10 mg/L RhB solution was reached after 30 and 15 minutes of visible light irradiation in current WO3 and Zn-doped WO3, respectively, according to the photodegradation assays. The photocatalytic degradation capability of Zn-doped WO3 was tested for the treatment of 150 mL of 5 mg/L RhB solution prepared from real textile effluent, and the results confirmed that Zn-doped WO3 has a high photocatalytic activity when exposed to visible light for the treatment of RhB from real textile effluent.