Impact of some pyrrolidinium ionic liquids on copper dissolution behavior in acidic environment: Experimental, morphological and theoretical insights

The inhibitive and adsorption activity of some pyrrolidinium ionic liquids (ILs) for the dissolution of copper in 1 M HNO3 solution was tested using chemical methods such as weight loss and electrochemical techniques; potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and electrical frequency modulation (EFM) techniques. The results indicated that the ionic liquids under investigation exhibited promising corrosion inhibitory performance in 1 M HNO3 and their efficiencies reached up to 85% at 0.05 mM. Also, an enhancement in the inhibition efficiency (% IE) accompanied the increase in inhibitor concentration. The polarization measurements suggested that these ionic liquid inhibitors act as mixed-type inhibitors. The adsorption of the ionic liquid inhibitors on the copper surface obey the Langmuir adsorption isotherm. Thermodynamic parameters were calculated and discussed. The surface morphology of the copper surface was examined using different techniques. Correlation between the calculated % IE from experiments and some quantum chemical parameters was established.