Study of Methylene Blue Adsorption onto Aminated Graphene Oxides at Varied Stirring Time

Abstract

Aminated graphene oxide (AGO) is one of graphene oxide (GO) derivatives that contained amine group (NH2). GO has a lot of oxygen-containing groups, such as hydroxyl, carboxyl, carbonyl, and epoxide functional groups, therefore it is hydrophilic and readily dispersed in water forming a stable colloidal suspension. This property was used to study decolorize of dye pollutant in water contamination. The presence of amine side chain in the molecule might contribute on improving hydrophilic properties of AGO compared to GO. Waste water containing harmful dyes such as methylene blue (MB) is one of the main problems in water contamination. In this work we study MB adsorption onto AGO surface. The experiments were carried out by mixing 50 mL of the MB solution in water (5 ppm; 0.25 mg) with 0.5 mL of dispersed AGO (0.5 mg / ml; 0.25 mg) in dimethylformamide (DMF), and then stirring at 1000 rpm at varied stirring times. The initial and final concentration of MB solutions after AGO adsorption were analyzed using spectroscopy. We obtained that AGO can adsorb MB in water, which the adsorption happened very fast until stirring time of 20 minutes. Addition of stirring time does not have significant change on MB concentration, which indicates that AGO adsorption capacity has saturated.