Congo red Dye Removal from Simulated Textile Wastewaters over a neat and silver Doped Zinc Oxide Nanoparticles. A Kinetics Study

摘要

The current study describes synthesis of zinc oxide nanoparticles (ZnONPs) by sol-gel method and its combination with silver particles (Ag/ZnONPs). Doping of zinc oxide with silver was carried out via using photo deposition method. The crystal structure of the synthesized catalysts was investigated with powder X-rays diffraction (PXRD) and specific surface area (BET). Surface morphology of the synthesized catalysts was investigated using scanning electron microscopy (SEM), and the ratio of element composition was estimated using energy dispersive X-rays (EDX). Functional groups of the surface were investigated using Fourier transform infrared spectroscopy (FTIR). The results of each of XRD and EDX showed that these materials have a hexagonal structure with a proposed formula of ZnO and Zno.49 O0.49 Ago.02. The activity of each of ZnO and Ag/ZnO was studied via removing of Congo red dye (CRD) from its aqueous solution over these catalysts. In this point different reaction parameters were investigated such as mass concentration of the used catalysts, dye concentration as well as effect of reaction temperature. Kinetic study of the reaction was performed by applying pseudo-first order according to Langmuir-Hinshelwood kinetic and the activation energy was calculated to be equal to 22 kJ.