Versatile Graphene oxide decorated by star shaped Zinc oxide nanocomposites with superior adsorption capacity and antimicrobial activity

Abstract

Graphene oxide–Zinc oxide (GO–ZnO) nanocomposite was prepared by a simple hydrothermal method. SEM and TEM analysis showed the presence of wide size range ZnO nanoparticles, which are distributed and firmly anchored onto the graphene oxide layers. The resulting GO–ZnO nanocomposite showed an extraordinary adsorption capacity and the fast adsorption rates for the removal of methylene blue (MB) and methyl orange (MO) from an aqueous solution. The adsorption isotherm, kinetics and thermodynamics were investigated in detail and the results showed that the adsorption data was best fitted to Langmuir adsorption isotherm model. The calculated monolayer adsorption capacity is 265.95 and 714.28 mg/g for MB and MO, respectively. Adsorption kinetics follows the pseudo-second-order kinetic equation. Thus, the as-prepared nanocomposite can be effectively utilized for the removal of organic dyes. The obtained results also suggest that the antimicrobial activities are caused by the membrane stress. The direct contact with sharp edges causes the membrane stress on cells, thereby resulting in the rupture. The physicochemical applications of graphene-based materials are specifically targeted to reduce the health and environmental risks. Keywords: GO–ZnO nanocomposite, Adsorption, Methylene blue, Methyl orange, Antimicrobial