Synthesis of Reduced Graphene Oxide from Cellulose and its Applications for Methylene Blue Adsorption

Abstract

This paper reports the synthesis and its application to the adsorption of methylene blue dye using graphene-oxide (GO) and reduced graphene-oxide (RGO). Among carbon-based nanomaterials, graphene and its derivatives have received remarkable attention due to their unique thermal, mechanical, and electronic properties and two-dimensional structure. The GO was synthesized by the modified Hummers method (chemical exfoliation) of graphite flake. This reaction produced graphite oxide (GrO) as an intermediate material. The synthesized materials, namely graphite, graphene oxide, and reduced graphene oxide, were characterized by XRD, FTIR, and Raman spectroscopy. These materials were tested to evaluate their adsorption capacity, concentration, contact time, and adsorbent weight on methylene blue, which was analyzed using a UV-vis spectrophotometer. The XRD pattern showed the formation of 2θ peaks at 24° to 26o for graphite, graphene oxide, and reduced graphene oxide, respectively. Furthermore, characterization by FTIR showed the appearance of O-H groups with peaks of 3358 cm-1 and 3342 cm-1 for graphene and reduced graphene oxides. Raman characterization indicated that reduced graphene oxide has a wavelength at the D-band peak of about 1375 cm-1 and the G-band peak reaching 1597 cm-1 with an ID/IG intensity ratio of 0.8. The adsorption test of methylene blue showed that reduced graphene oxide had the best adsorption capacity with an adsorbent, concentration, optimum time, and highest adsorption capacity value of 25 mg, 30 ppm, 45 minutes, and 15.642 mg/g. The adsorption process followed the Langmuir isotherm rule, as evidenced by the R2 value of 0.9881.