Physioelectrochemical Study on the Inhibition of Copper Corrosion inAcidic Solution by Newly Synthesized Organic Compound

Copper has wide applications in industry owing to its high electrical and thermal conductivities,mechanical workability, and its relatively noble properties. It is employed extensively forcondensers, evaporators, and fractionating columns in the chemical industry [1]. A variety ofenvironmental factors can easily cause corrosion of copper. Scale and corrosion products have anegative effect on heat transfer, and they cause a decrease in heating efficiency of the equipment.That is why periodic cleaning in hydrochloric acid and nitric acid pickling solutions arenecessary. In order to reduce the corrosion of metals, several techniques have been applied. Theuse of chemical inhibitors is one of the most practical methods for the protection againstcorrosion in acidic media. Most of the excellent acid inhibitors are organic compounds containingnitrogen, oxygen, phosphorus and sulphur. Studies of the relation between adsorption andcorrosion inhibition are of considerable importance. Copper dissolution involves at first, singleelectron transfer process leading to oxidation thereby forming Cu(I) complex .The action ofinhibitors is electrochemical in nature and involves the discharge of positively charged particlesat the cathodic area that form an adsorbed layer. The adsorption of inhibitors takes place by virtueof their physical and chemical properties and also depends on the nature of metal and the type ofthe electrolyte solution used [2]. Herein, we investigated inhibitive effect of organic compound(Fig. 1) on the corrosion of copper in sulfuric acid by means of potentiodynamic polarization andelectrochemical impedance spectroscopy (EIS). The results of investigation show that thiscompound is a good inhibitor against the corrosion of copper in acidic solution and its inhibitionefficiency increase by increasing the inhibitor concentration. The adsorption of organiccompound onto the copper surface followed the Langmuir adsorption model with the negativefree energy of adsorption. Quantum chemical calculations were employed to give further insightinto the mechanism of inhibition action of inhibitor.

کلیدواژه ها:

Copper ، Inhibitor ، Potentiodynamic polarization ، electrochemical impedance spectroscopy