Corrosion Inhibition of Mild Steel in 1 M HCl Using 5-(3-Methylphenyl)-4-((4-Nitrobenzylidene)amino)-4H-1,2,4-Triazole-3-Thiol: Experimental and Theoretical Insights
نویسندگان
1 Technical Engineering College, Middle Technical University, P.O. Box: 10001, Baghdad, Iraq
2 Oil and Gas Engineering Department, University of Technology, P.O. Box: 10001, Baghdad, Iraq
3 Al-Karkh University of Science, Baghdad P.O. Box: 10001, Baghdad, Iraq
4 Al-Ayen Scientific Research Center, Al-Ayen Iraqi University, AUIQ, An Nasiriyah, P.O. Box: 64004, Thi Qar, Iraq
doi
10.30509/pccc.2025.167462.1359چکیده
This study investigates the corrosion inhibition performance of 5-(3-methylphenyl)-4-((4-nitrobenzylidene)amino)-4H-1,2,4-triazole-3-thiol (MNATT) for mild steel in 1 M HCl, using both experimental weight loss techniques and Density Functional Theory (DFT) calculations. Weight loss experiments were conducted at MNATT concentrations ranging from 0.1 to 1.0 mM and immersion times between 1 and 48 hours. The highest inhibition efficiency of 88.6 % was observed at 0.5 mM after 5 hours of immersion. A temperature-dependent study conducted at 303-333 °K revealed a mild improvement in inhibition performance with rising temperature, indicating thermal stability of the adsorbed layer. Adsorption behavior followed the Langmuir isotherm, and the calculated standard free energy of adsorption ( = –14.33 kJ·mol⁻¹) confirmed that the adsorption mechanism is physisorption. Complementary DFT analysis showed a HOMO-LUMO energy gap (ΔE = 3.532 eV) and identified electron-rich active sites, supporting the molecule’s ability to interact with the metal surface. These findings demonstrate that MNATT is a promising, low-concentration, surface-friendly corrosion inhibitor for mild steel in acidic environments.
