Synthesis of water-dispersible graphene-modified magnetic polypyrrole nanocomposite and its ability to efficiently adsorb methylene blue from aqueous solution

A graphene-modified, magnetic polypyrrole nanocomposite (Fe3O4@PPy/RGO) was fabricated through a facile chemical route and its application as an adsorbent for the removal of a dye was also demonstrated. The as-prepared Fe3O4@PPy/RGO nanocomposite was characterized by Fourier transform infrared (FT-IR) spectroscopy, transmission electron microscopy (TEM), X-ray diffraction (XRD), N-2 adsorption-desorption, and zeta potential analysis techniques. The Fe3O4@PPy/RGO nanocomposite showed excellent water dispersibility because of the hydrophilicity of Fe3O4 and RGO. Adsorption experiments indicated that Fe3O4@PPy/RGO adsorbs methylene blue fast and efficiently, with an adsorption capacity of up to 270.3 mg g(-1). The kinetic adsorption data fit the pseudo-second-order model and the isotherm data followed the Langmuir model. Additionally, adsorption of MB on Fe3O4@PPy/RGO also can utilize the electrostatic interaction and pi-pi interaction between Fe3O4@PPy/RGO and MB. Moreover, compared to other nanoparticle adsorbents, the as-prepared Fe3O4@PPy/RGO is highly flexible and easy to operate and retrieve. Most importantly, it is easy to disperse, which enables its potential application in wastewater treatment. (C) 2015 Elsevier B.V. All rights reserved.