Experimental and theoretical insights into the corrosion inhibition activity of a novel pyrazoline derivative for mild steel in 1.0 M HCl

Abstract

This study focuses on the use of a new synthesized compound namely 2-(4-(3-phenyl-4,5-dihydro-1H-pyrazol-5-yl)phenoxy)acetic acid (PYR-3) as an efficient sustainable inhibitor for the corrosion of mild steel in 1 M HCl solution.For this purpose, the current assessment was conducted using a range of experimental and theoretical techniques such as weight loss, electrochemical impedance spectroscopy (EIS), potentiodynamic‎polarization (PDP), DFT computations and molecular dynamic (MD) simulations.The experimental results revealed that the studied compound give a maximum inhibition efficiency of 87 % and the inhibition ability increased with raising of the inhibitor concentrations. Further, this inhibitor effectively reduced the corrosion rate of MS which is afforded by the adsorption of this compound onto the MS surface obeyed the Langmuir adsorption isotherm via physico-chemical adsorption. The adsorption parameters such as adsorption equilibrium constant (K_ads) and free energy of adsorption (ΔG⁰_ads) were calculated and discussed. To provide further insight into theinteraction’s mechanism between our synthesized compound with the iron surface in an acidic medium, computational calculations such as DFT and MD simulations could beof interesting. Overall, the obtained results from theoretical point of view correlate well with the electrochemical parameters.