Ethanedihydrazide as a Corrosion Inhibitor for Iron in 3.5% NaCl Solutions

Ayman H Ahmed; El-Sayed M Sherif; Hany S Abdo; Ehab Said Gad

doi:10.1021/acsomega.1c01422

Ethanedihydrazide as a Corrosion Inhibitor for Iron in 3.5% NaCl Solutions

ACS Omega. 2021 May 27;6(22):14525-14532. doi: 10.1021/acsomega.1c01422. eCollection 2021 Jun 8.

Authors

Ayman H Ahmed^{1

2}, El-Sayed M Sherif³, Hany S Abdo^{3

4}, Ehab Said Gad^{1

2}

Affiliations

¹ Chemistry Department, College of Science and Arts, Jouf University, Gurayat, Saudi Arabia.
² Department of Chemistry, Faculty of Science, Al-Azhar University, Nasr City, Cairo, Egypt.
³ Center of Excellence for Research in Engineering Materials (CEREM), College of Engineering, King Saud University, P.O. Box 800, Al-Riyadh 11421, Saudi Arabia.
⁴ Mechanical Design and Materials Department, Faculty of Energy Engineering, Aswan University, Aswan 81521, Egypt.

Abstract

Corrosion of iron in sodium chloride (3.5% wt) solutions and its inhibition by ethanedihydrazide (EH) have been reported. Electrochemical impedance spectroscopy (EIS), cyclic potentiodynamic polarization (CPP), and change of current with time at -475 mV (Ag/AgCl) measurements were employed in this study. Scanning electron microscopy (SEM) and energy-dispersive X-ray (EDX) techniques were utilized to report surface morphology and elemental analysis, respectively. The presence of 5 × 10^-5 M EH was found to inhibit the corrosion of iron, and the effect of inhibition profoundly increased with an increase in EH concentration up to 1 × 10^-4 M and further to 5 × 10^-4 M. The low values of corrosion current and high corrosion resistance, which were obtained from the EIS, CPP, and change of current with time experiments, affirmed the adequacy of EH as a corrosion inhibitor for iron. Surface investigations demonstrated that the chloride solution without EH molecules causes severe corrosion, while the coexistence of EH within the chloride solution greatly minimizes the acuteness of chloride, particularly pitting corrosion.