Voltammetric and Raman microspectroscopic studies on artificial copper pits grown in simulated potable water

Christy, Andrew G.; Lowe, Adrian; Otieno-Alego, Vincent; Stoll, Murray; Webster, Richard D.

doi:10.1023/b:jach.0000009923.35223.f8

Cited by 62 publications

(67 citation statements)

References 41 publications

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“…In the spectra are observed two broad peaks centred almost at 525 cm -1 and 625 cm -1 which are unambiguously related to cuprous oxide, cuprite (Cu 2 O), in according to the Raman reference spectrum for cuprous oxide and the spectrum bands. 13,14 Likewise, this result accords with the copper corrosion products reported for the water-copper system where the oxides film have been mostly composed by cuprous oxide. 1,10 Electrochemical impedance spectroscopy at OCP .…”

Section: Copper Surface Characterizationsupporting

confidence: 89%

Electrochemical behavior of copper in drinking water: evaluation of dissolution process at low anodic overpotential

Ríos¹,

Calderón²,

Nogueira³

2011

J. Braz. Chem. Soc.

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O comportamento eletroquímico do cobre em água potável foi estudado por polarização potenciodinâmica e espectroscopia de impedância eletroquímica em até quatro dias depois de imersão em condições hidrodinâmicas diferentes. Os resultados de impedância foram interpretados usando modelos de circuito equivalente, os quais mostraram um aumento da espessura do filme com o tempo, que impede a difusão de espécies de cobre através da camada de óxido de cobre formada. Essa camada de óxido é maior em condição de estagnação. A baixos sobrepotenciais anódicos, os diagramas de impedância apresentam pelo menos quatro constantes de tempo que poderiam ser explicadas pela existência de diferentes pocessos faradaicos, a adsorção/dessorção de espécies intermediárias, processos de difusão e a formação de uma camada de óxido na superfície de cobre. Na região anódica, a resistência total à corrosão diminui, possivelmente devido à dissolução das espécies de cobre e ao aumento da difusão através da camada de óxido, principalmente sob condições hidrodinâmicas.The electrochemical behavior of copper in near-neutral aerated tap water was studied by potentiodynamic polarization and electrochemical impedance spectroscopy up to four days of immersion under different hydrodynamic conditions. The impedance results were interpreted by equivalent circuit that showed an increasing film thickness with time that hinders the diffusion of copper species across the oxide layer, which is larger in stagnating condition. At low anodic overpotential, copper impedance presents at least four time constants that could be explained by faradaic processes, adsorption/desorption of intermediate species, diffusion controlled process and oxide layer formation on copper surface. In the anodic region, the overall corrosion resistance decreases possibly due to the dissolution of copper species and the increase of diffusion across the oxide layer, mainly under hydrodynamic condition.

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Section: Copper Surface Characterizationsupporting

confidence: 89%

Electrochemical behavior of copper in drinking water: evaluation of dissolution process at low anodic overpotential

Ríos¹,

Calderón²,

Nogueira³

2011

J. Braz. Chem. Soc.

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“…For theset ypes of corrosion experiments,t he onset of the initial passivation typically occurs at variable potentials over several hundred millivolts because of the randomness of the individual micropitting events, and it has been shown that the dissolution largely proceeds with two electrons through the oxidation of Cu 0 to Cu 2 + . [41] Similar voltammetric responses wereo bserved for Cu electrodes modified with different amountso ft he MWCNTcoating solution ( Figure 1, colored lines), although much smaller oxidation peaks were obtained for electrodes modified with 10 drops, indicating that very high loadings of CNTsr educed the corrosion processes. The decrease in corrosion currents at very high loadings could either be attributedt ot he reduced access of the SO 4 2À anionst ot he Cu surfaceo rt othe reduced ability of corrosion products to be transported away from the electrode surface, thereby supporting electrode passivation.…”

Section: Voltammetric Behavior Of Copper Electrodes Modified With Porsupporting

confidence: 57%

“…The sulfate anion is known to be very aggressive in voltammetrically inducing copper dissolution, which leads to the formation of deep pits and reduces passivation events. [41] Althoughc opperi sdifferent to the carbon materials that are usually used for the base electrode, for the purposes of this study it is assumed that attachment of the MWCNTs occurs in as imilar manner.T his is ar easonablea s- www.chemelectrochem.org sumption ast he drop-casting procedure of CNTs( or most other carbon nanomaterials) does not produce ac ovalently bondedattachment, but one where the materialsticks through weak physisorption interactions. Furthermore, there was no evidencet hat the MWCNTsd etached from the copper electrode when placed in an electrolyte solution after the dropcasting procedure.…”

Section: Introductionmentioning

confidence: 99%

Assessments of Surface Coverage after Nanomaterials are Drop Cast onto Electrodes for Electroanalytical Applications

et al. 2015

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The drop‐casting method for the suspension of nanomaterials on conducting surfaces is a commonly used procedure for evaluating the electrochemical properties of the drop‐cast materials. In this study, we pinpoint a key limitation of the method, which may lead to misinterpretation of the obtained data, especially when evaluating heterogeneous electron‐transfer rates. The electrochemical responses recorded at 1 mm‐diameter copper electrodes modified with porous layers of drop‐cast multiwalled carbon nanotubes (MWCNTs) in 0.1 M Na2SO4 aqueous solutions were examined. Standard amounts of the MWCNTs that are typically used for the drop‐casting procedure (1 mg MWCNT in 1 mL of dimethylformamide) were deposited drop wise on the surface of the copper electrodes. Layers of MWCNTs were progressively built up on the electrode surface by varying the number of drops from 0 to 10. The ability of the MWCNTs to cover and prevent diffusion to the base copper electrode was assessed by performing oxidative cyclic (CV) and linear‐sweep voltammetry (LSV) experiments in the presence of aggressive SO42− supporting electrolyte, where a large oxidative current indicated the occurrence of corroding copper metal. It was demonstrated that a total of 10 drops of the coating solution (equivalent to 640 μg cm−2 of MWCNTs per unit area) was still insufficient in providing complete coverage over the underlying electrode surface (as a corrosion current was still observed), even though considerably lower CNT loadings have been applied in many literature reports. The electrochemical results indicate that, for experiments that utilize the drop‐casting procedure to modify electrode surfaces, it cannot be assumed that the base electrode, nor the pore structure of the coating material, does not significantly contribute to the overall observed voltammetric response.

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“…The molecule contains nitrogen atoms and it is also useful in preventing copper staining and tarnishing [5]. The electropolishing process reported to be inhibited with different ratio by the addition of some organic aldehydes [6]and Organic compounds containing polar groups, including nitrogen, sulfur, oxygen, and heterocyclic compounds with polar functional groups and conjugated double bonds have been reported to inhibit copper corrosion [7][8][9][10][11][12][13]. The inhibiting action of these organic compounds is usually attributed to their interactions with the copper surface via their adsorption.…”

Section: Introductionmentioning

confidence: 99%

Studying Copper Electropolishing Inhibition in Presence of Some Organic Alcohols

Attia¹,

Elmelegy²,

El‐Batouti³

et al. 2016

Port. Electrochim. Acta

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Electro polishing is defined as anodic corrosion. The issue of the effects of corrosion on structural integrity of metal surfaces has been a question of concern for some time. The uses of chemical corrosion inhibitors are common in production and processing operations. Nevertheless, the challenge is to develop a new class of corrosion inhibitors to protect the materials, due to the economic importance of copper there are several researches deals with acceleration and inhibition of this process. In this paper the electropolishing process inhibited with different ratio by addition of some organic alcohols (methanol, ethanol,propanol, and isopropanol) by addition with concentration (2, 5, 10, 15, 20, 25 and 30 %) .The results reveal that these organic alcohols have a strongest inhibitive effect ranging from8. 7 -53.8 % and the thermodynamic parameters were present.

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Voltammetric and Raman microspectroscopic studies on artificial copper pits grown in simulated potable water

Cited by 62 publications

References 41 publications

Electrochemical behavior of copper in drinking water: evaluation of dissolution process at low anodic overpotential

Electrochemical behavior of copper in drinking water: evaluation of dissolution process at low anodic overpotential

Assessments of Surface Coverage after Nanomaterials are Drop Cast onto Electrodes for Electroanalytical Applications

Studying Copper Electropolishing Inhibition in Presence of Some Organic Alcohols

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