Spectral Migration of Fluorescence in Graphene Oxide Aqueous Dispersions: Evidence for Excited-State Proton Transfer

Konkena, Bharathi and Vasudevan, Sukumaran (2014) Spectral Migration of Fluorescence in Graphene Oxide Aqueous Dispersions: Evidence for Excited-State Proton Transfer. In: JOURNAL OF PHYSICAL CHEMISTRY LETTERS, 5 (1). pp. 1-7.

PDF Jou_Phy_Che_Let_5-1_1_2014.pdf - Published Version Restricted to Registered users only Download (4MB) | Request a copy

Abstract

Aqueous dispersions of graphene oxide (GO) exhibit strong pH-dependent fluorescence in the visible that originates, in part, from the oxygenated functionalities present. Here we examine the spectral migration on nanosecond time-scales of the pH dependent features in the fluorescence spectra. We show, from time-resolved emission spectra (TRES) constructed from the wavelength dependent fluorescence decay curves, that the migration is associated with excited state proton transfer. Both `intramolecular' and `intermolecular' transfer involving the quasi-molecular oxygenated aromatic fragments are observed. As a prerequisite to the time-resolved measurements, we have correlated the changes in the steady state fluorescence spectra with the sequence of dissociation events that occur in GO dispersions at different values of pH.

Item Type:	Journal Article
Publication:	JOURNAL OF PHYSICAL CHEMISTRY LETTERS
Publisher:	AMER CHEMICAL SOC
Additional Information:	Copyright for this article belongs to the AMER CHEMICAL SOC, USA
Department/Centre:	Division of Chemical Sciences > Inorganic & Physical Chemistry
Date Deposited:	10 Feb 2014 10:17
Last Modified:	10 Feb 2014 10:17
URI:	http://eprints.iisc.ac.in/id/eprint/48330

Actions (login required)

View Item