**2.2.1.3 Reference electrode**

A saturated calomel electrode (SCE) was used as a reference electrode. The values of the electrode potential in the present work are given relative to this electrode. The potential value for the SCE is 0.242 V vs. NHE at 25 oC. SCE was periodically calibrated and checked.

Electrochemical experiments were performed using the Potentiostat / Galvanostat Wenking PGS 95. i-E curves were recorded by computer software from the same company (Model ECT). Except otherwise stated, the potential was swept linearly from starting potential into the positive direction up to a certain anodic potential with a given scan rate and then reversed with the same scan rate up to the starting cathodic potential.

For each run, freshly prepared solutions as well as a cleaned set of electrodes were used. All experiments were conducted at a given temperature (± 0.5 oC) with the help of circular water thermostat. After polymer film formation, the working electrode was withdrawn from the cell, rinsed thoroughly with a doubly distilled water to remove any traces of the formed constituents in the reaction medium. The deposited polymer film was subjected to different experimental tests to characterize it.
