Hydrazone-based green corrosion inhibitors for API grade carbon steel in HCl: Insights from electrochemical, XPS, and computational studies

International audienceCorrosion protection of carbon steel (CS) is an important challenge in the industry field. The search for an effective protection approach is still a hot research question. In the present work, three hydrazone derivatives (HZ-OH, HZ-Me, and HZ-Cl) were used in 1.0 M HCl solution for API grade CS corrosion mitigation. Their corrosion inhibition performance was evaluated by electrochemical tests while steel surface was analyzed by X-ray photoelectron spectroscopy (XPS), contact angle and scanning electron microscope (SEM). Electrochemical tests showed an inhibition efficiency between 91% and 98% for CS exposed to acidic solution containing 0.05 mol/L of the three hydrazone derivatives. All compounds were classified as mixed type inhibitors, inhibiting both cathodic and anodic corrosion reactions. XPS showed that inhibitor molecules formed a stable layer on steel surface through chemical and physical interactions. The adsorption of molecules onto the steel surface was found to follow Langmuir model. DFT and MD simulations were used to investigate the interaction of hydrazones with Fen (n = 1–4) and Fe2O3(001) surface, respectively. They confirmed that the inhibitor with two hydroxy groups (HZ-OH) had a greater interaction with iron atoms. © 2021 Elsevier B.V

Enhanced corrosion inhibition of carbon steel in HCl solution by a newly synthesized hydrazone derivative: Mechanism exploration from electrochemical, XPS, and computational studies

International audienceThe corrosion inhibition properties of a synthesized hydrazone derivative namely, 1-(4-isopropyl phenyl) -2- (2,4-dinitrophenyl) (HYD (iso)) on API 5L-X60 carbon steel (CS) in 1.0 M HCl solution were evaluated by chemical, electrochemical, X-ray photoelectron spectroscopy (XPS) and theoretical studies. The obtained results revealed that the tested compound acted as a good corrosion inhibitor with inhibition efficiency of 96.32% at a concentration of 5 × 10−3 M. The polarization technique indicated that the HYD (iso) belonged to mixed-type inhibitors, preventing simultaneously anodic and cathodic reactions. The binding between the HYD (iso)'s molecule and CS surface follows a Langmuir adsorption type model and its inhibition mechanism is assisted by physical and chemical interactions. Scanning electron microscope (SEM) and contact angle analyses were performed to examine the surface morphology of inhibited and uninhibited samples. Additionally, theoretical studies using Density Functional Theory (DFT) and molecular dynamics (MD) simulation were performed to explore the most reactive sites of the hydrazone molecule and its adsorption mechanism