Investigation of the adsorption of methyl orange by Ag-TiO2/GO nanocomposite

In this study, Ag-TiO2 and Ag-TiO2/GO nanomaterials were prepared and then characterized via different analysis methods such as XRD, SEM, EDX, Raman, and BET.The adsorption capacity of prepared samples was investigated by removal of methyl orange, as a model organic pollutant, from aqueous solutions. Based on results, Ag-TiO2-GO nanocomposite demonstrated an excellent activity over Ag-TiO2 sample. To understand the nature of the adsorption process, the equilibrium adsorption isotherms were studied. Based on results, for Ag-TiO2 and Ag-TiO2/GO, Freundlich and Langmuir isotherm models with a correlation coefficient of 0.989 and 0.993 fitted the experimental data, respectively. According to the Langmuir isotherm model, the maximum adsorption capacity of Ag-TiO2/GO nanocomposite for adsorption of methyl orange was about 69.44 mg/g, which was about 3 times the adsorption capacity of Ag-TiO2. Furthermore, negative ΔG0 and ΔH0 values resulted from thermodynamic investigation suggested that the adsorption of methyl orange onto Ag-TiO2/GO nanocomposite was simultaneous and exothermic in nature, respectively.