Synthesis, characterization of graphene oxide composites and investigation of their use in dye removal from aqueous solutions

In this study, a new nanocomposite adsorbent material (MGOH) was produced by using magnetite, graphene oxide (GO) and hydroxyapatite (HAP) to contribute to the treatment of wastewater through the adsorption method. The magnetite found in the nanocomposite structure provides magnetic properties. Thus, the adsorbent offers the opportunity to be easily removed from its environment by magnetic effect applied from outside. For nanocomposite production, GO was first produced by the modified Hummers method, and magnetite was produced by the co-precipitation method. Nanocomposite was prepared by combining magnetite, GO and HAP in the co-precipitation process. The product obtained was characterized using analysis methods such as XRD, FTIR, SEM-EDX, BET. Textile dye (Maxilon® Blue GRL (300%)) removal behavior of MGOH from aqueous solution was investigated under such conditions; changing initial dye concentration (1000-3000 mg/L), time, pH (3-9) and temperature (25°C -55°C). The maximum adsorption capacity was found to be 120.73 mg/g at 55℃ temperature, 3000 mg/L dye concentration and pH 7. The data obtained show that the adsorption process proceeds kinetically in accordance with the pseudo-second order kinetic model, that the thermodynamic reaction is endothermic, and the adsorption of dye molecules is compatible with the Langmuir isotherm model. Additionally, the reusability of the adsorbent material in its third use was found to be 66.47%.