Corrosion inhibition of copper in {HNO3} solution using thiophene and its derivatives

By Fouda, A. S.; Wahed, H. A. Abdul
Published in Arabian Journal of Chemistry NULL 2016

Abstract

Abstract The corrosion behavior of copper in the presence of thiophene (T) and some of its derivatives [2-thiophene carboxylic acid (TC) and 2-thienyl ethanol (TE)] has been investigated in 2 M {HNO3} solution using electrochemical frequency modulation (EFM), electrochemical impedance spectroscopy (EIS), potentiodynamic polarization and weight loss techniques. Polarization studies showed that these compounds act as mixed type inhibitors. {EFM} technique provides a new tool for electrochemical corrosion monitoring and was used as an effective method for corrosion rate determination. In {EFM} measurements corrosion current density was determined without prior knowledge of Tafel slopes. Inhibition efficiency of these compounds has been found to vary with concentrations of the compounds and temperature. The adsorption of these compounds on the copper surface from the acid solution has been found to obey Langmuir adsorption isotherm. The thermodynamic activation parameters of copper corrosion in 2 M {HNO3} were determined and discussed. The results obtained from EFM, EIS, Tafel and weight loss measurements were in good agreement.

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