Exfoliation of graphite as flexible SERS substrate with high dye adsorption capacity for Rhodamine 6G

Sykam, Nagaraju and Jayram, Dhanpal Naidu and Rao, Mohan G (2019) Exfoliation of graphite as flexible SERS substrate with high dye adsorption capacity for Rhodamine 6G. In: APPLIED SURFACE SCIENCE, 471 . pp. 375-386.

PDF App_Sur_Sci_471_375_2019.pdf - Published Version Restricted to Registered users only Download (4MB) | Request a copy

Abstract

Adsorption is one of the most important processes in wastewater treatment, especially for dye removal. In addition to adsorption, there must be a vigilant technique, such as Surface Enhanced Raman spectroscopy (SERS), for detection of low concentration of dye molecules to detect water foiling. Herein, we report a simple, low cost, rapid and efficient technique for the production of exfoliated graphite (EG) under microwave irradiation at 800 W in 1 min, as excellent adsorption material for Rhodamine 6G (R6G) dye. The effect of adsorption process parameters such as pH, contact time, isotherm models (Langmuir and Freundlich) and kinetic models (pseudo-first and pseudo-second-order) on dye removal under aqueous solutions, were investigated. The maximum adsorption capacity for R6G dye is 212.72 (+/- 5.3) mg/g. Meanwhile compressing of EG, into a flexible graphite sheet (FGS) demonstrates responsive SEAS for R6G molecules up to detection limit of 10(-7) mol/L. However, with silver nanoparticle incorporation, the detection limit increases up to 10(-)(12) mol/L. Performance of flexible sheet checked over a month by rubbing sheet through paper and cloth doesn't have any impact on the synthesis of exfoliated graphite. Aging factor of the sheet also shows reproducible SEAS spectra after a month. These are the highest reported values fill today, for adsorption of R6G dye on Exfoliated graphite, with reasonable SEAS detection.

Item Type:	Journal Article
Publication:	APPLIED SURFACE SCIENCE
Publisher:	ELSEVIER SCIENCE BV
Additional Information:	Copyright of this article belongs to ELSEVIER SCIENCE BV
Keywords:	Exfoliated graphite; Adsorption; Flexible graphite sheet; Microwave irradiation; SERS
Department/Centre:	Division of Physical & Mathematical Sciences > Instrumentation Appiled Physics
Date Deposited:	08 Feb 2019 06:04
Last Modified:	08 Feb 2019 06:04
URI:	http://eprints.iisc.ac.in/id/eprint/61627

Actions (login required)

View Item