Synthesizing magnetic graphene oxide nanomaterial (GO‐Fe3O4) and kinetic modelling of methylene blue adsorption from water

Abstract

AbstractMethylene blue (MB) is a frequently used dye in several industries that is detrimental both to human health and aquatic ecosystems. Graphene oxide (GO) has the application potential for dye removal from wastewater due to its high specific surface area; however, it suffers from a labourious separation step. In this work, magnetic GO nanostructure was prepared by co‐precipitation of ferrous salts in presence of GO to achieve a GO‐Fe3O4 hybrid. By choosing the proper ratio of GO to Fe3O4, the specific surface area of 280.26 m2/g could provide excellent adsorption capacity; the superparamagnetic property of the prepared adsorbent also ensures its magnetic separation from aqueous solutions. The results of adsorption experiments revealed that, within 2 min, 93%, 80%, and 50% of MB were separated from the solutions of 100, 120, 150 mg/L dye concentration, respectively. The adsorption of MB followed a pseudo‐first‐order kinetic model, and the equilibrium isotherm study indicated that experimental data were well fitted to the Langmuir isotherm model. The impact of pH and adsorbent dosage were investigated, and the results showed that the amount of adsorbed MB onto the GO‐Fe3O4 was sharply increased to 231.6 and 246 mg/g by increasing pH and adsorbent dosage up to 6 and 15 g, respectively. Thermodynamic parameters indicated that the adsorption process of MB is endothermic and spontaneous. In addition, GO‐Fe3O4 revealed a good regeneration ability by using ethanol as the desorbent. These results suggest that the proposed adsorbent has promising potential in removing dye from water resources.