Nickel adsorption studies on synthesized graphene oxide and magnetic graphene oxide
Loading...
Date
2016
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Punjab Agricultural University Ludhiana
Abstract
Adsorptive properties of magnetic graphene oxide (MGO) nanocomposite are investigated for
facile removal of Ni (II) ions from water. Graphene oxide (GO), magnetic oxide nanoparticles
(MO NPs) and magnetic graphene oxide (MGO) were characterized by X-ray diffractiion
pattern (XRD), 57Fe Mössbauer spectroscopy, Vibrating sample magnetometer (VSM),
Transmission electron microscopy (TEM), Scanning electron microscopy (SEM) and FT-IR
spectroscopy as analytical tools. TEM images of MGO reveal uniform spherical homogenous
distribution of MO NPs with agglomeration over the graphene nanosheet. Mössbauer analysis
shows significant ferric oxide phase along with super paramagnetic maghemite and goethite
phase. A comparative analysis of the GO, MO NPs and MGO for the removal of Ni (II) ions
from synthetic waste water was carried out by batch method and Ni (II) content was estimated
spectrophotometrically. The effect of operating parameters including adsorbent dose,
temperature, contact time, pH, initial metal ion concentration of Ni (II) were studied.
Optimum pH for adsorption was 10. Values of ∆Go, ∆H˚ and ∆S˚ were found to be negative
for all adsorbents, indicating spontaneous and exothermic nature of adsorption process. NPs
showed small variation in the percentage removal. The trend for the percentage removal of Ni
(II) in the descending order was MGO > MO NPs > GO. Langmuir and Freundlich isotherms
fit the data better than D-R isotherms. The advantage of MGO is enhancement of adsorption
potential due to presence of MO NPs along with GO, their magnetic separation after
adsorption and solubility problem of GO is overcome.
Description
Keywords
Nickel adsorption, graphene oxide, magnetic graphene oxide