Congo red (CR) an anionic dye (C32H22N6Na2O6S2 and Molar Mass as 696.7 gmol-1) used in the present work (Fig.1a) and zinc acetate dihydrate were purchased from LOBA Chemie Company, India. Methylene blue (MB) a cationic dye (C16H18N3SCl and Molar Mass of 319.85 gmol-1) as shown in Fig.1b, was purchased from Oxford laboratory reagent Co. Zinc acetate used for the preparation of nanoparticles ZnO and sodium hydroxide were purchased from Biotech laboratory chemicals company. Ethyl alcohol was purchased from ADWIC company. Dilute solutions of HNO3 and NaOH (BDH) were prepared to control the pH during the experiments.
Fig. 1Chemical Structure of (a) Congo Red and (b) Methylene blue dye.
Preparation of ZnO nanoparticles (Adsorbent)
Zinc oxide (ZnO) nanoparticles was obtained by co-precipitation method as in the following procedure: a beaker …show more content…
Scanning electron microscopy/Energy-dispersive X-ray spectroscopy employed to analyze the size, morphology and structures of the ZnO and ZnO/CR nanoparticles. The elemental analysis of both ZnO and ZnO/CR were determined by SEM-EDS using ZAF method standardless quantitative analysis [14]. The crystal structure of ZnO and ZnO/CR was investigated by X-ray diffraction (XRD)using = 0.1542 nm and 2 values started from 10 to 80. In addition the structural properties of ZnO and ZnO/CR were analyzed by Shimadzu FTIR spectrometer (from400 to 4000 cm-1) at room temperature. pH values measured by pH meter (HANNA). Perkin Elmer Lambda 35,UV–vis spectrophotometer was used for determining [MB] and [CR] samples employing the standard calibration curve of MB and CR at the maximum wavelengths 665 nm and 495nm,