Synthesis and Characterization of Multiwalled Carbon Nanotubes Decorated by ZnO and Ag2O for Using to Remove Methyl Green and Erythrosin B Dyes from Their Aqueous Solutions

A new nanocomposite for multiwalled carbon nanotubes with zinc oxide and silver oxide was prepared by utilizing hydrothermal method with methanol as solvent.Zinc oxide (ZnO) and silver oxide (Ag2O) were synthesized using co-precipitation method under basic medium.They were identified by several techniques such as UV-Vis, X-ray powder diffraction (XRD), scanning electron microscopy (SEM) and EDX analysis.The crystal size of the prepared nano compounds was revealed 17.6, 26.8, 20.3 and 21.5nm for MWCNT (after their functionalized by utilizing acids mixture from sulfuric and nitric acid by ratio 3:1(v/v)), ZnO, Ag2O and MWCNTs/ZnO & Ag2O nanocomposite respectively.The batch adsorption was used for removing two different class as cationic and anionic dyes from its aqueous solutions under various conditions such as pH level, temperature, contact time and agitation speed, the data exhibited a high value to remove dyes methyl green (MG) and erythrosin B (EB) onto the surface nanocomposite were 96.4 and 99.71% respectively.Adsorption equilibrium isotherm appeared the Langmuir model is more fitted than Freundlich to remove erythrosin B dyes with adsorption capacity 184.9 mg/g, while the adsorbed of methyl green dye more fitted with Freundlich isotherm and adsorption capacity is 836.9 mg/g.Thermodynamic parameters (G , H and S ) have been computed and revealed the negative values for the free energy.