Adsorption-photodegradation synergetic removal of methylene blue from aqueous solution by NiO/graphene oxide nanocomposite

Nickel oxide/graphene oxide (NiO/GO) nanocomposite was prepared by a hydrothermal method combining a subsequent calcination process. X-ray diffraction (XRD), Raman spectrometer (Raman), high resolution transmission electron microscopy (HRTEM), selected area electron diffraction (SAED) and X-ray photoelectron spectroscopy (XPS) methods were used for the characterization of nanocomposite. Removal of aromatic heterocyclic dye methylene blue (MB) from aqueous solution using adsorption and photodegradation activity of NiO/GO nanocomposite was investigated. The effects of NiO/GO nanocomposite dose, pH, and contact time on the removal efficiency of MB were also investigated. Compared with that in the dark, NiO/GO nanocomposite shows a faster and higher removal efficiency by the photodegradation and adsorption under visible light irradiation. A remarkable removal efficiency of MB achieved 97.54% by NiO/GO nanocomposite after 2 h. It could be concluded that synergy of photodegradation and adsorption has a significant progress for removal of MB under visible light compared with that of only adsorption without light. (C) 2015 Elsevier B.V. All rights reserved.