Single layer graphene as a stable and transparent electrode for the measurement of non-aqueous electrogenerated chemiluminescence and charge transfer inverse photoemission

In this work we explore the use of single layer graphene (SLG) obtained by chemical vapor deposition as a transparent electrode material for use in coupled electrochemical and spectroscopic experiments in non-aqueous media through electrogenerated chemiluminescence (ECL). SLG was used with classical ECL luminophores, rubrene, tris(2,2′-bypyridine)-ruthenium(II) and 9,10-diphenylanthracene in an inert environment to generate stable electrochemical responses and measure light emission through the material. SLG displayed excellent stability during electrochemical potential stepping and voltammetry in a window that spanned at least from -2.4 V to +1.8 V versus a QRE in acetonitrile and acetonitrile/benzene with sufficiently facile electron transfer properties to yield stable voltammetric cycling and ECL. SLG electrodes patterned with poly-tetrafluoroethylene permitted the stable generation of radical ions on an SLG microelectrode to be studied through Scanning Electrochemical Microscopy (SECM) in the generation/collection mode. The transparency of graphene was used to obtain accurate spectral responses in ECL: while inner filter effects are known to cause a shift in peak emission wavelength of spectroelectrochemical studies, the use of SLG electrodes with detection through the graphene window reduced apparent peak shifts by up to 10 nm in wavelength. This work introduces SLG as a transparent, electrochemically active and chemically stable platform for studying ECL reactivity in the radical annihilation mode, where large electrode polarizations could compromise the chemical stability of other existing transparent electrodes. Additionally, steady state radical annihilation ECL was explored via thin layer cells and SECM.

Name thesis:degree_name

M.S.

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Chemistry

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2015

Author dc:creator

• Cristarella, Teresa

Contributors dc:contributor

• Rodriguez-Lopez, Joaquin

• Electrochemistry
• electrogenerated chemiluminescence
• single layer graphene

Statement dc:rights

• Copyright 2014 Teresa Cristarella

Language dc:language

en

Handle dc:identifier

http://hdl.handle.net/2142/73017

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/73017