Three indazole derivatives as corrosion inhibitors of copper in a neutral chloride solution

In this work, three halogeno-indazole compounds were investigated for corrosion inhibition of copper in 3.0 wt% NaCl solution using potentiodynamic polarization measurement, electrochemical impedance spectroscopy, and X-ray diffraction (XRD) analysis. The electrochemical results revealed that all of these organics are mixed-type inhibitors with an inhibitive ability order: 4-CIA > 4-BIA > 4-FIA, which was further confirmed by observations with field emission scanning electron microscope (FE-SEM) and atomic force microscope (AFM). Their favourable performance is ascribed to the formation of inhibitor-adsorption films on copper. Furthermore, theoretical calculations showed the electronic structure of studied compounds and their optimized adsorption configurations on the copper surface.