Photocatalytic degradation of methylene blue using ZnO and 2%Fe–ZnO semiconductor nanomaterials synthesized by sol–gel method: a comparative study

Abstract

ZnO and 2%Fe–ZnO nanomaterials were prepared by using a low-cost sol–gel method. The synthesized nanomaterials were characterized by X-ray diffraction (XRD), Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray Spectroscopy (EDX). The XRD and SEM studies reveal that the synthesized nanomaterials have a hexagonal wurtzite structure with average crystalline size ~ 22 to 23 nm. EDX analysis confirmed the composition and purity of synthesized nanomaterial. The photocatalytic activity of synthesized nanomaterials was monitored using the spectrophotometric method. Also, the photocatalytic removal of methylene blue (MB) dye from its aqueous solution by using ZnO and 2%Fe–ZnO nanopowder under UV light irradiation was studied. The effect of various parameters such as pH of dye solution, dye concentration, contact time and catalyst dose were investigated. Results of the current study demonstrated that, the maximum degradation using ZnO was 86% and that for 2%Fe–ZnO was 92% (under the optimum condition initial dye concentration = 10 mg/L and pH = 2). This study showed that 2%Fe–ZnO is a promising and better photocatalysts than ZnO.