Electrochemical study on using aminated MIL–101(Cr) as corrosion inhibitor for mild steel in acidic environment


Purpose
The purpose of this paper is to confirm the importance of using metal–organic frameworks (MOFs) in the field of corrosion control due to their potential use as corrosion inhibitors.


Design/methodology/approach
NH2–MIL–101(Cr), an amine-functionalized chromium-based MOF [Cr(III)-MOF], was prepared by solvothermal technique. Thereafter, Cr-MOF was used as an anticorrosion additive for mild steel (MS) in 1 m HCl solution. This inhibition behavior was tested by electrochemical tests including electrochemical impedance spectroscopy and potentiodynamic polarization (PDP).


Findings
Increasing the added amount of Cr-MOF enhances its inhibition performance, which attained 96.40% at 30 ppm. The obtained data from PDP measurements describe Cr-MOF as a mixed-type inhibitor. Based on SEM/EDS and FTIR analysis, the adsorption of Cr-MOF on the surface of MS that prevents MS corrosion has been demonstrated. Furthermore, Langmuir model is the most adequate adsorption isotherm for the obtained experimental data.


Originality/value
This study revealed that NH2–MIL–101(Cr), an amine-functionalized chromium-based MOF (Cr(III)-MOF), is a potential corrosion inhibitor for MS in 1 m HCl solution.
