Graphene and graphene oxide as effective adsorbents toward anionic and cationic dyes

Ramesha, GK and Kumara, Vijaya A and Muralidhara, HB and Sampath, S (2011) Graphene and graphene oxide as effective adsorbents toward anionic and cationic dyes. In: Journal of Colloid and Interface Science, 361 (1). pp. 270-277.

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Abstract

In the present study, exfoliated graphene oxide (EGO) and reduced graphene oxide (rGO) have been used for the adsorption of various charged dyes such as methylene blue, methyl violet, rhodamine B, and orange G from aqueous solutions. EGO consists of single layer of graphite decorated with oxygen containing functional groups such as carboxyl, epoxy, ketone, and hydroxyl groups in its basal and edge planes. Consequently, the large negative charge density available in aqueous solutions helps in the effective adsorption of cationic dyes on EGO while the adsorption is negligible for anionic dyes. On the other hand, rGO that has high surface area does not possess as high a negative charge and is found to be very good adsorbent for anionic dyes. The adsorption process is followed using UV-Visible spectroscopy, while the material before and after adsorption has been characterized using physicochemical and spectroscopic techniques. Various isotherms have been used to fit the data, and kinetic parameters were evaluated. Raman and FT-IR spectroscopic data yield information on the interactions of dyes with the adsorbent. (C) 2011 Elsevier Inc. All rights reserved.

Item Type:	Journal Article
Publication:	Journal of Colloid and Interface Science
Publisher:	Elsevier Science
Additional Information:	Copyright of this article belongs to Elsevier Science.
Keywords:	Graphene oxide;Reduced graphene oxide;Dyes;Vibrational spectroscopy;Adsorption isotherm.
Department/Centre:	Division of Chemical Sciences > Inorganic & Physical Chemistry
Date Deposited:	03 Aug 2011 05:37
Last Modified:	03 Aug 2011 05:37
URI:	http://eprints.iisc.ac.in/id/eprint/39589

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