Polyethersulfone enwrapped graphene oxide porous particles for water treatment

Recent studies showed that graphene oxide (GO) presented high adsorption capacities to various water contaminants. However, the high water dispersibility of GO restricted its practical applications in wastewater treatment since ultrahigh centrifugation was necessary after the adsorption process. In this study, a facile method was presented by enwrapping GO in porous particles to remove dyes and other pollutions from wastewater. Polyethersulfone (PES) was chosen as the matrix to enwrap GO through a liquid-liquid phase separation process, the PES/GO porous particles showed a dense skin layer and a porous structures of the inside. Methylene blue (MB), a cationic dye, was chosen as the adsorbate to investigate the adsorption capability, kinetics and isotherms of the prepared particles, and the particles displayed an adsorption capacity up to 62.5 mg/g for MB dye. Meanwhile, the effect of contacting time, initial concentration, temperature, and pH value on the adsorption capacity was studied. The experimental data of MB adsorption fitted the pseudo-second-order kinetic model and the Langmuir isotherm very well, and the adsorption process was controlled by the intraparticle diffusion. Moreover, the results indicated that the PES/GO porous particles showed good selective adsorbability to cationic dyes, such as MB and methyl violet. (C) 2012 Elsevier B.V. All rights reserved.