Evaluation of an aza dipyrromethene derivative as a green corrosion inhibitor via experimental and theoretical methods

Abstract

1,7-dihydroxy-aza-dipyrromethene (DAD) was utilized as an eco-friendly corrosion inhibitor against highly acidic media on a mild steel surface. Weight loss, potentiodynamic polarization measurements, and electrochemical impedance spectroscopy were applied to investigate the inhibition mechanism at a temperature range of 298–328 K. The surface morphology of the metallic surface was monitored using the scanning electron microscopy (SEM) technique. Weight loss and electrochemical measurements revealed that DAD demonstrates good inhibition performance (inhibition efficiency: 79–83 %) against highly acidic media as a mixed-type inhibitor. Global reactivity parameters, Fukui functions, and stabilization energies (E(2)) were calculated to discuss potential local electron donor sites.