Inhibition of Copper Corrosion Studied by Electrochemical and EQCN Techniques

Matjaž Finšgar^a, Ingrid Milošev*^a and Boris Pihlar^b
a Jo`ef Stefan Institute, Department of Physical and Organic Chemistry, Jamova 39, SI-1000 Ljubljana, Slovenia
^b Faculty of Chemistry and Chemical Technology, University of Ljubljana, A{ker~eva 5, SI-1000 Ljubljana, Slovenia.
  E-mail: ingrid.milosev@ijs.si

Abstract
The inhibition of copper corrosion in 3% NaCl solution in the absence and presence of an organic inhibitor was studied by using different electrochemical techniques, i.e. cyclic voltammetry, linear polarization, Tafel plots and potentiodynamic curves on bulk Cu electrode. Two organic inhibitors were investigated (3-amino-1,2,4-triazole – ATA and benzotriazole – BTAH). Experimental results show that BTAH is a more effective inhibitor than ATA. Electrochemical quartz crystal nanobalance (EQCN) was applied to deposit copper on a gold electrode by using controlled potential or controlled current deposition method. It was found that deposition of copper was better using controlled potential technique. The process of film formation on copper plated on gold was studied in 3 % sodium chloride in the absence and presence of ATA or BTAH. Selected corrosion inhibitors showed very rapid interaction between the metal surface and organic molecules. Results have shown that in-situ EQCN is a powerful technique for obtaining information on corrosion inhibition and its mechanism.

Keywords: Copper, chlorides, EQCN, benzotriazole, 3-amino-1,2,4-triazole.