A combination of modeling and experimental approaches to investigate the novel nicotinohydrazone Schiff base and its complexes with Zn(II) and ZrO(II) as inhibitors for mild-steel corrosion in molar HCl

Two novel metal-complexes of 5-sodium sulfonate-2-hydroxybenzylidene)nicotinohydrazone (H2LCs) with Zn2+ and ZrO2+ ions were synthesized and characterized (ZnLCs and ZrOLCs), respectively. Condensation of nicotinohydrazide with salicylaldehyde-5-sodium sulfonate salt afforded H2LCs. Inhibition effectiveness of H2LCs and its complexes with Zn(II) and Zr(II) for M-steel in a 1.0 M HCl solution was examined by electrochemical (EOCP vs. time, impedance spectroscopy (EIS) and potentiodynamic polarization (PDP)) methods. In comparison with H2LCs, ZnLCs and ZrOLCs display enhanced protection capacities. Particularly, the ZrOLCs compound displays higher protection power, and the efficacy is up to 97.4% at 5 ? 10-4 mol L - 1 at 303 K. PDP studies exhibited that the as-prepared additives act as inhibitors of the mixed-kind, and adsorbed on M-steel surface via chemisorption following the Langmuir isotherm model. The surface morphology inspections (FE-SEM/EDX, and FT-IR) display that the M-steel interface was inhibited by titled compounds. To get a preferable comprehension of the adsorption of compound species on the steel interface, a detailed modeling investigation was accomplished using Monte Carlo (MC) simulation and DFT calculations. QSAR model also investigated via multiple linear regression method. The current report delivers very significant outcomes in designing and fabricating sustainable inhibitors with high protection capacity. (c)& nbsp;2021 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved.