The characterisation of PbO2–coated electrodes prepared from aqueous methanesulfonic acid under controlled
deposition conditions
The characterisation of PbO2–coated electrodes prepared from aqueous methanesulfonic acid under controlled
deposition conditions
A series of PbO2 coatings on planar carbon substrates has been prepared by anodic deposition in aqueous methanesulfonic acid (MSA) under galvanostatic conditions. The effect of four experimental parameters, i.e., lead(II) methanesulfonate and MSA concentrations, current density, and temperature was analysed. Surface characterisation by XRD, SEM-EDX, and AFM has provided information about the structural (phase distribution, degree of crystallinity, and crystallite size), morphological (crystallite shape, degree of porosity), and tribological (surface roughness) properties of the PbO2 coatings, respectively. Electrochemical studies based on linear and cyclic voltammetry allowed comparison between electrodes prepared in MSA and classical electrodes prepared in HNO3. Pure ?- or ?-PbO2 and ? + ? mixtures were obtained depending on the conditions, being temperature the most influential deposition parameter. A temperature rise caused a transition to pure ?-PbO2 and led to a higher degree of crystallinity with a progressive increase of crystallite size, always within the range of 10–30 nm, as well as to a remarkably higher roughness, from smooth (35–50 nm rms) to rough (up to 500 nm rms) surfaces. Low MSA and high lead(II) methanesulfonate concentrations were required to avoid the formation of excessively porous powdery coatings, as well as cracks, pits, and holes. Most of the coatings obtained in MSA were uniform, nanocrystalline, and moderately rough. Their electrocatalytic behaviour was comparable to that of the electrodes prepared in HNO3, showing an O2-overpotential of +0.66 V in 0.05 M Na2SO4 at pH 3.0. Such coatings can then be envisaged as suitable anodes for energy and water treatment applications. Prolonged electrolysis has shown their stability against leaching.
electrochemical advanced oxidation processes, electrodeposition, lead dioxide, methanesulfonic acid, surface characterisation
2163-2172
Sirés, I.
85e095d9-c3fa-48e2-aff3-65f0f4b2e4b4
Low, C.T.J
96216991-4076-41f7-b21b-bbc3c27ed8c5
Ponce de Leon, C.
508a312e-75ff-4bcb-9151-dacc424d755c
Walsh, F.C
309528e7-062e-439b-af40-9309bc91efb2
15 February 2010
Sirés, I.
85e095d9-c3fa-48e2-aff3-65f0f4b2e4b4
Low, C.T.J
96216991-4076-41f7-b21b-bbc3c27ed8c5
Ponce de Leon, C.
508a312e-75ff-4bcb-9151-dacc424d755c
Walsh, F.C
309528e7-062e-439b-af40-9309bc91efb2
Sirés, I., Low, C.T.J, Ponce de Leon, C. and Walsh, F.C
(2010)
The characterisation of PbO2–coated electrodes prepared from aqueous methanesulfonic acid under controlled
deposition conditions.
Electrochimica Acta, 55 (6), .
(doi:10.1016/j.electacta.2009.11.051).
Abstract
A series of PbO2 coatings on planar carbon substrates has been prepared by anodic deposition in aqueous methanesulfonic acid (MSA) under galvanostatic conditions. The effect of four experimental parameters, i.e., lead(II) methanesulfonate and MSA concentrations, current density, and temperature was analysed. Surface characterisation by XRD, SEM-EDX, and AFM has provided information about the structural (phase distribution, degree of crystallinity, and crystallite size), morphological (crystallite shape, degree of porosity), and tribological (surface roughness) properties of the PbO2 coatings, respectively. Electrochemical studies based on linear and cyclic voltammetry allowed comparison between electrodes prepared in MSA and classical electrodes prepared in HNO3. Pure ?- or ?-PbO2 and ? + ? mixtures were obtained depending on the conditions, being temperature the most influential deposition parameter. A temperature rise caused a transition to pure ?-PbO2 and led to a higher degree of crystallinity with a progressive increase of crystallite size, always within the range of 10–30 nm, as well as to a remarkably higher roughness, from smooth (35–50 nm rms) to rough (up to 500 nm rms) surfaces. Low MSA and high lead(II) methanesulfonate concentrations were required to avoid the formation of excessively porous powdery coatings, as well as cracks, pits, and holes. Most of the coatings obtained in MSA were uniform, nanocrystalline, and moderately rough. Their electrocatalytic behaviour was comparable to that of the electrodes prepared in HNO3, showing an O2-overpotential of +0.66 V in 0.05 M Na2SO4 at pH 3.0. Such coatings can then be envisaged as suitable anodes for energy and water treatment applications. Prolonged electrolysis has shown their stability against leaching.
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e-pub ahead of print date: 22 November 2009
Published date: 15 February 2010
Keywords:
electrochemical advanced oxidation processes, electrodeposition, lead dioxide, methanesulfonic acid, surface characterisation
Organisations:
Engineering Mats & Surface Engineerg Gp
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Local EPrints ID: 69890
URI: http://eprints.soton.ac.uk/id/eprint/69890
ISSN: 0013-4686
PURE UUID: 068fec9f-2d38-46ad-827e-481e0ec1009a
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Date deposited: 09 Dec 2009
Last modified: 14 Mar 2024 02:50
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Author:
I. Sirés
Author:
C.T.J Low
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