Electrochemical characterisation of ultrathin carbon nanofiber-chitosan multi-layer films

M A Murphy, G D Wilcox, R H Dahm, F Marken

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9 Citations (Scopus)

Abstract

Carbon nanofibers can be oxidized and solubilised in alkaline or neutral aqueous media. Deposition of the solution by solvent evaporation allows well-defined amounts,of carbon nanofiber material to be deposited onto tin-doped indium oxide (ITO) electrodes and studied electrochemically. Next, a layer-by-layer deposition process is employed to produce homogeneous and ultrathin films of carbon nanofibers with a chitosan binder with controlled thickness. Films with a thickness similar to the nanofiber diameter, 50-200 nm, are produced and characterized via electron microscopy, conductivity measurements, and quartz crystal microbalance gravimetry. Electrochemically, even very thin films of hydrophilised carbon nanofibers are readily detected due to their (pseudo-)capacitive current response (ca. 150 F g(-1) over a limited potential range). Electrochemical reactions, such as the oxidation of hydroquinone in aqueous phosphate buffer, are shown to be catalysed by the presence of hydrophilised carbon nanofiber fragments (with respect to the same process at a bare ITO electrode). Based on voltammetric responses. the electron transfer across a barrier between carbon nanofibers and the ITO substrate is identified as rate limiting in the presence of chitosan. Possible applications of ultrathin carbon/chitosan deposits, for example as transparent carbon electrodes. are discussed.
Original languageEnglish
Pages (from-to)924-931
Number of pages8
JournalIndian Journal of Chemistry Section a-Inorganic Bio-Inorganic Physical Theoretical & Analytical Chemistry
Volume44
Issue number5
Publication statusPublished - 2005

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Carbon nanofibers
Multilayer films
Chitosan
carbon
ITO (semiconductors)
Electrodes
Carbon
electrodes
Tin
Ultrathin films
Gravimetric analysis
Quartz crystal microbalances
Nanofibers
gravimetry
Electron microscopy
Binders
Buffers
Evaporation
Deposits
quartz crystals

Cite this

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title = "Electrochemical characterisation of ultrathin carbon nanofiber-chitosan multi-layer films",
abstract = "Carbon nanofibers can be oxidized and solubilised in alkaline or neutral aqueous media. Deposition of the solution by solvent evaporation allows well-defined amounts,of carbon nanofiber material to be deposited onto tin-doped indium oxide (ITO) electrodes and studied electrochemically. Next, a layer-by-layer deposition process is employed to produce homogeneous and ultrathin films of carbon nanofibers with a chitosan binder with controlled thickness. Films with a thickness similar to the nanofiber diameter, 50-200 nm, are produced and characterized via electron microscopy, conductivity measurements, and quartz crystal microbalance gravimetry. Electrochemically, even very thin films of hydrophilised carbon nanofibers are readily detected due to their (pseudo-)capacitive current response (ca. 150 F g(-1) over a limited potential range). Electrochemical reactions, such as the oxidation of hydroquinone in aqueous phosphate buffer, are shown to be catalysed by the presence of hydrophilised carbon nanofiber fragments (with respect to the same process at a bare ITO electrode). Based on voltammetric responses. the electron transfer across a barrier between carbon nanofibers and the ITO substrate is identified as rate limiting in the presence of chitosan. Possible applications of ultrathin carbon/chitosan deposits, for example as transparent carbon electrodes. are discussed.",
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TY - JOUR

T1 - Electrochemical characterisation of ultrathin carbon nanofiber-chitosan multi-layer films

AU - Murphy, M A

AU - Wilcox, G D

AU - Dahm, R H

AU - Marken, F

N1 - ID number: ISI:000229441900007

PY - 2005

Y1 - 2005

N2 - Carbon nanofibers can be oxidized and solubilised in alkaline or neutral aqueous media. Deposition of the solution by solvent evaporation allows well-defined amounts,of carbon nanofiber material to be deposited onto tin-doped indium oxide (ITO) electrodes and studied electrochemically. Next, a layer-by-layer deposition process is employed to produce homogeneous and ultrathin films of carbon nanofibers with a chitosan binder with controlled thickness. Films with a thickness similar to the nanofiber diameter, 50-200 nm, are produced and characterized via electron microscopy, conductivity measurements, and quartz crystal microbalance gravimetry. Electrochemically, even very thin films of hydrophilised carbon nanofibers are readily detected due to their (pseudo-)capacitive current response (ca. 150 F g(-1) over a limited potential range). Electrochemical reactions, such as the oxidation of hydroquinone in aqueous phosphate buffer, are shown to be catalysed by the presence of hydrophilised carbon nanofiber fragments (with respect to the same process at a bare ITO electrode). Based on voltammetric responses. the electron transfer across a barrier between carbon nanofibers and the ITO substrate is identified as rate limiting in the presence of chitosan. Possible applications of ultrathin carbon/chitosan deposits, for example as transparent carbon electrodes. are discussed.

AB - Carbon nanofibers can be oxidized and solubilised in alkaline or neutral aqueous media. Deposition of the solution by solvent evaporation allows well-defined amounts,of carbon nanofiber material to be deposited onto tin-doped indium oxide (ITO) electrodes and studied electrochemically. Next, a layer-by-layer deposition process is employed to produce homogeneous and ultrathin films of carbon nanofibers with a chitosan binder with controlled thickness. Films with a thickness similar to the nanofiber diameter, 50-200 nm, are produced and characterized via electron microscopy, conductivity measurements, and quartz crystal microbalance gravimetry. Electrochemically, even very thin films of hydrophilised carbon nanofibers are readily detected due to their (pseudo-)capacitive current response (ca. 150 F g(-1) over a limited potential range). Electrochemical reactions, such as the oxidation of hydroquinone in aqueous phosphate buffer, are shown to be catalysed by the presence of hydrophilised carbon nanofiber fragments (with respect to the same process at a bare ITO electrode). Based on voltammetric responses. the electron transfer across a barrier between carbon nanofibers and the ITO substrate is identified as rate limiting in the presence of chitosan. Possible applications of ultrathin carbon/chitosan deposits, for example as transparent carbon electrodes. are discussed.

M3 - Article

VL - 44

SP - 924

EP - 931

JO - Indian Journal of Chemistry Section a-Inorganic Bio-Inorganic Physical Theoretical & Analytical Chemistry

JF - Indian Journal of Chemistry Section a-Inorganic Bio-Inorganic Physical Theoretical & Analytical Chemistry

SN - 0376-4710

IS - 5

ER -