Kinetic studies of 4-chlorophenol adsorption on the reduced graphene oxides
Institute of Electronic Materials Technology (ITME), Warszawa 01919, Poland
J. Jagiełło1, K. Kuśmierek2, M. Sankowska2, A. Świątkowski2
1 Institute of Electronic Materials Technology, 01-919 Warsaw, Poland
2 Institute of Chemistry, Military University of Technology, 00-908 Warsaw, Poland
The graphene oxide was prepared by a modified Hummers method . Two samples so obtained graphene oxide were chemically reduced by HI or HBr. To characterize the reduced graphene oxides, designated as rGOHI and rGOHBr, the nitrogen adsorption/desorption isotherms at 77.4 K, the total oxygen content, Raman spectra as well as SEM images were determined. The specific surface area (SBET) and total oxygen content were 65 m2/g and 13% for rGOHI, and 35 m2/g and 20% for rGOHBr, respectively, which indicates that the type of reductant used significantly affect the properties of the resulting materials.
The adsorption properties of these materials were tested in aqueous solutions with respect to 4-chlorophenol. The adsorption equilibriums were achieved after about 60 min for the rGOHI and after about 90 min for the rGOHBr. For comparison, the adsorption kinetics of the 4-chlorophenol on the most commonly used adsorbents – activated carbons, was reached after approximately 6 hours [2,3]. The kinetics data were fitted well to the pseudo-second order model with the coefficient of determination (R2) values greater than 0.99. The rate constants k2 obtained for rGOHI and rGOHBr were 0.731 and 0.537 g/mmol·min, respectively. The potential use of these materials for the preparation of the SPME fibers was also investigated. The results showed that the reduced graphene oxides are promising materials for microextraction of organic contaminants from water.
 W.S. Hummers, R.E. Offeman, Preparation of graphitic oxide.J. Am. Chem. Soc. 80 (1958) 1339.
 B. Koumanova, P. Peeva-Antova, Z. Yaneva, Adsorption of 4-chlorophenol from aqueous solutions on activated carbon - kinetic study. J. Univ. Chem. Technol. Metallurgy 40 (2005) 213.
 K. Kuśmierek, M. Sankowska, A. Świątkowski, Kinetic and equilibrium studies of simultaneous adsorption of monochlorophenols and chlorophenoxy herbicides on activated carbon. Desalin. Water Treat. 52 (2014) 178.
Presentation: Poster at Nano PL 2014, Symposium A, by Ludwika Lipińska
See On-line Journal of Nano PL 2014
Submitted: 2014-10-02 07:05 Revised: 2014-10-02 07:06