To investigate the interaction mechanisms of the three additives, the chronoamperometry (CA) technique is applied to measure the current of the electrode at different times. the CA testing setup consists of an electrochemical workstation with 3 electrodes system which are:

         Working Electrode: It is the electrode on which the reduction reaction of Cu2+ occurs. It is usually a rotating disk electrode (RDE) for electrochemical studies to investigate the reaction mechanisms related to the redox chemistry. It rotates during the experiments inducing a flux of the analyte to the electrode. The working electrode used in this study is a platinum RDE.

         Counter Electrode: It is an electrode where an electrical current is expected to flow. It passes all the current needed to balance the current observed at the working electrode, but its current and potential are not measured. The counter electrode used in this study is a platinum electrode.

         Reference Electrode: It is an electrode which has a stable and well-known electrode potential. Its only role is to act as reference in measuring and controlling the working electrodes potential and at no point does it pass any current. The reference electrode used in this study is Ag-AgCl electrode. Hg-Hg2SO4 mercurous sulfate electrode is not used for the consideration of environmental pollution.

Chronoamperometry(CA) is an electrochemical technique in which the potential of the working electrode is stepped and the resulting current from faradic processes occurring at the electrode (caused by the potential step) is monitored as a function of time. In CA, the potential is stepped from Init E to either High E or Low E depending on the Init P/N and may then be stepped back. 

Limited information about the identity of the electrolyzed species can be obtained from the ratio of the peak oxidation current versus the peak reduction current. However, as with all pulsed techniques, chronoamperometry generates high charging currents, which decay exponentially with time as any RC circuit. The Faradaic current--which is due to electron transfer events and is most often the current component of interest--decays as described in the Cottrell equation. In most electrochemical cells this decay is much slower than the charging decay--cells with no supporting electrolyte are notable exceptions. Most commonly investigated with a three electrode system. Since the current is integrated over relatively longer time intervals, chronoamperometry gives a better signal to noise ratio in comparison to other amperometric technique.

In order to investigate the electrochemical characteristics of single additive and additive interaction under different potentials applied and additive concentrations, the tests were conducted to measure the current density of the Cu solution with the CA technique. The discussion of single additive and additive interaction are given in the following sections, respectively.