title: Synthesis and Characterisation of Fluorescent Carbon Nanodots Produced in Ionic Liquids by Laser Ablation.
abstract: Carbon nanodots (C-dots) with an average size of 1.5 and 3.0 nm were produced by laser ablation in different imidazolium ionic liquids (ILs), namely, 1-n-butyl-3-methylimidazolium tetrafluoroborate (BMI.BF4 ), 1-n-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide (BMI.NTf2 ) and 1-n-octyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide (OMI.NTf2 ). The mean size of the nanoparticles is influenced by the imidazolium alkyl side chain but not by the nature of the anion. However, by varying the anion (BF4 vs. NTf2 ) it was possible to detect a significant modification of the fluorescence properties. The C-dots are much probably stabilised by an electrostatic layer of the IL and this interaction has played an important role with regard to the formation, stabilisation and photoluminescence properties of the nanodots. A tuneable broadband fluorescence emission from the colloidal suspension was observed under ultraviolet/visible excitation with fluorescence lifetimes fitted by a multi-exponential decay with average values around 7 ns.
authors.affiliation: Instituto de Física, UFRGS, Av. Bento Gonçalves, 9500, CEP 91501-970, Porto Alegre, RS (Brazil).
authors.forename: Hemerson P S
authors.initials: HP
authors.lastname: Castro
authors.affiliation: Instituto de Química, UFRGS, Av. Bento Gonçalves, 9500, 91501-970, Porto Alegre, RS (Brazil).
authors.forename: Virgínia S
authors.initials: VS
authors.lastname: Souza
authors.affiliation: Instituto de Química, UFRGS, Av. Bento Gonçalves, 9500, 91501-970, Porto Alegre, RS (Brazil). jackson.scholten@ufrgs.br.
authors.forename: Jackson D
authors.initials: JD
authors.lastname: Scholten
authors.affiliation: Instituto de Física, UFRGS, Av. Bento Gonçalves, 9500, CEP 91501-970, Porto Alegre, RS (Brazil).
authors.forename: Janine H
authors.initials: JH
authors.lastname: Dias
authors.affiliation: Department of Chemistry, UVIC, Victoria, BC, V8W 3V6 (Canada).
authors.forename: Jesum A
authors.initials: JA
authors.lastname: Fernandes
authors.affiliation: Instituto de Química, UFRGS, Av. Bento Gonçalves, 9500, 91501-970, Porto Alegre, RS (Brazil).
authors.forename: Fabiano S
authors.initials: FS
authors.lastname: Rodembusch
authors.affiliation: National Center for Electron Microscopy, LBNL, Berkeley, California 94720 (USA).
authors.forename: Roberto
authors.initials: R
authors.lastname: Dos Reis
authors.affiliation: Instituto de Química, UFRGS, Av. Bento Gonçalves, 9500, 91501-970, Porto Alegre, RS (Brazil). jairton.dupont@nottingham.ac.uk.|School of Chemistry, University of Nottingham, University Park, Nottingham, NG7 2RD (UK). jairton.dupont@nottingham.ac.uk.
authors.forename: Jairton
authors.initials: J
authors.lastname: Dupont
authors.affiliation: Instituto de Física, UFRGS, Av. Bento Gonçalves, 9500, CEP 91501-970, Porto Alegre, RS (Brazil).
authors.forename: Sérgio R
authors.initials: SR
authors.lastname: Teixeira
authors.affiliation: Instituto de Física, UFRGS, Av. Bento Gonçalves, 9500, CEP 91501-970, Porto Alegre, RS (Brazil). rego@if.ufrgs.br.
authors.forename: Ricardo R B
authors.initials: RR
authors.lastname: Correia
keywords: carbon; fluorescence; ionic liquids; laser ablation; nanoparticles