Multidimensional analysis for corrosion inhibition by new pyrazoles on mild steel in acidic environment: Experimental and computational approach

Abstract

Inhibition of mild steel (M.S) corrosion by some pyrazole-2-acetohydrazide derivatives, namely; ((E)-2-(3,5-dimethyl-1H-pyrazol-1-yl)-N'-(4-hydroxy-3-methoxybenzylidene)acetohydrazide (DHA) and (E)-2-(3,5-dimethyl-1H-pyrazol-1-yl)-N'-(furan-2-ylmethylene)acetohydrazide (DFA)) in 1 M HCl was studied using weight loss (WL), electrochemical impedance spectroscopy (EIS), and potentiodynamic polarization (PDP) measurements and Scanning Electron Microscopy (SEM) allowed M.S surface analysis. On the other hand, computational investigations (DFT and Monte-Carlo simulation (MCs), and Molecular dynamic simulations (MDs)) have been apprehended. The efficiency of inhibition increases as the concentration of inhibitor increases, and it also increases as the temperature increases. At a concentration of 10−3 M, the anti-corrosion performance of DHA was 97.6% and 85.9% for DFA, respectively, according to polarization measurements. PDP were used to obtain both anodic and cathodic inhibitions. The Langmuir isotherm was followed in the adsorption of DFA & DHA onto steel surfaces. Furthermore, when the inhibitor was present, SEM pictures exhibited better surface protection, which was matched with a molecular dynamic simulation that confirmed perfect surface alignment between the inhibitor and the M.S-surface. Experiments, DFT computations, MCs, and MDs are all in agreement.