The effect of 5-nitroindazole as an inhibitor for the corrosion of copper in a 3.0% NaCl solution

The inhibition effect of 5-nitroindazole on the corrosion of copper in a 3.0% NaCl solution was investigated with the methods of weight loss, electrochemical tests, scanning electronic microscopy (SEM) and theoretical calculations. The weight loss and electrochemical results revealed that 5-nitroindazole is a mixed-type inhibitor with the inhibition efficiency is up to 99% at 0.4 mM, which was further confirmed by SEM observation. The adsorption of the inhibitor molecule on the copper surface was found to obey the Langmuir adsorption isotherm. The quantum chemical calculations and molecular dynamics simulation showed that 5-nitroindazole is adsorbed strongly on the copper surface in a parallel mode through the indazole ring.