Differential capacitance and electrochemical impedance study of surfactant adsorption on polycrystalline Ni electrode

作者：Anastopoulos A G^*; Papoutsis A D; Papaderakis A A

来源：Journal of Solid State Electrochemistry, 2015, 19(8): 2369-2377.

DOI：10.1007/s10008-015-2879-7

• Nickel electrode
• Organophosphorus
• Inhibitors
• Capacitive charging
• Irreversible adsorption
• Non-capacitive response

The adsorption of neutral organophosphorous compounds on a charged polycrystalline Ni electrode is studied by differential capacitance and impedance measurements in methanol solutions. Analysis of capacitance measurements reveals that tributylphosphine oxide, tri(n)octylphosphine oxide, and triphenylphosphine follow Langmuir adsorption isotherm. Saturation capacitance C (sat), potential of maximum adsorption E (max), limiting surface concentration I" (max), and standard Gibbs energy of adsorption Delta G (max) (o) at E (max) are determined. The cathodic reduction of (NiOCH3)(ads) film formed on Ni surface at positive potentials, introducing a faradaic contribution in addition to the electrostatic charging of the interface, is supported by linear sweep voltammetric and impedance measurements. High values of electrode coverage and strong depression of faradaic currents are attained, indicating that these adsorbates may be suitable as corrosion inhibitors.

• 出版日期2015-8