Irradiation time dependent of the ZnO/GO composite formation on the photodegradation of Rhodamine B

Abstract

Rhodamine B (Rh B) is one of the dyes used in the dyeing of paints, acrylic, and fabrics as well as biological products. A high concentration of Rh B is highly toxic and dangerous to living organisms when directly discharged into water. Therefore, in this study, the degradation of Rh B in water by zinc oxide/graphene oxide (ZnO/GO) composite was investigated. The zinc oxide (ZnO) was recovered from zinc ash, waste from galvanization industries, by acid leaching process using hydrochloric acid (HCl), while the graphene oxide (GO) was synthesized by modified Hummers method. The nanocomposite of ZnO/GO was synthesized using microwave irradiation and characterized by means of Field Emission Scanning Electron Microscope (FE-SEM), X-Ray Diffraction (XRD), and Fourier Transform Infrared (FTIR). The effect of irradiation time during ZnO/GO nanocomposite formation on the photocatalysis activity of the ZnO/GO in degrading Rhodamine B under UV rays was studied. The irradiation time was varied for 6, 8, and 10 minutes. The characterization results confirm that ZnO, GO, and ZnO/GO have been successfully synthesized. The ZnO/GO nanocomposite was also responsive to UV rays and able to degrade Rh B, as one of the examples of water pollutants. The highest degradation of Rhodamine B is achieved by the ZnO/GO nanocomposite prepared at 10 minutes of irradiation. The results of this study demonstrate that microwave irradiation time affects the ability of the nanocomposite to degrade Rhodamine B.