Efficient removal of phenol and aniline from aqueous solutions using graphene oxide/polypyrrole composites

A novel approach was developed to fabricate graphene oxide/polypyrrole (GO/PPy) composites via dielectric barrier discharge (DBD) plasma technique in nitrogen and room temperature conditions, and characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transformed infrared spectroscopy (FT-IR), thermal gravimetric analysis (TGA), and X-ray photoelectron spectroscopy (XPS) in details. The sorption of phenol and aniline on the GO/PPy composites from aqueous solutions was investigated as a function of contact time, solid content, pH and initial concentrations of sorbates. The sorption capacities of phenol and aniline on the GO/PPy composites were much higher than those of phenol and aniline on many of today's materials. The sorption of phenol and aniline on GO/PPy composites obeyed the Langmuir model, and was mainly attributed to ion exchange, pi-pi electron donor-acceptor (EDA) interaction, hydrophobic interaction and Lewis acid-base interaction. The thermodynamic parameters calculated from the temperature-dependent sorption isotherms suggested that phenol and aniline sorption on GO/PPy composites was an endothermic and spontaneous process. Moreover, GO/PPy composites could be regenerated through the phenol and aniline desorption by ethanol, and cycling reused without obvious decrease of sorption capacity. All these results indicated that the GO/PPy composites were suitable materials for the preconcentration of phenol and aniline from aqueous solutions in environmental pollution management. (C) 2014 Elsevier B.V. All rights reserved.