Evaluating the adsorption and corrosion inhibition capabilities of Pyridinium - P - Toluene Sulphonate on MS in 1 M HCl medium: An experimental and theoretical study

Abstract

Mild steel (MS) is a reasonably priced construction alloy that can be utilized for a broad array of tasks in a variety of settings, Viz. mild acidic conditions with minor precautions. The quantitative assessment of MS's corrosion behavior in 1 M acidic (HCl) medium, at temperatures between (298–328 K), both in the presence and absence of the inhibitor Pyridinium - P - Toluene Sulphonate (PPTS), was examined by utilizing weight loss (WL) measurement, potentiodynamic polarization (PDP), and electrochemical impedance spectroscopy (EIS) methods. All these approaches were accompanied by surface characterization approaches utilizing scanning electron microscope (SEM) and atomic force microscope (AFM). This analysis is unique in that it uses WL approaches for each of the three indices to investigate the efficacy of a novel, reasonably priced, non-toxic, and environmentally friendly corrosion inhibitor (PPTS) for MS under 1 M acidic conditions. Significant corrosion resistance was achieved with the introduction of the tested inhibitor, and PPTS demonstrated a very promising inhibition efficiency (IE %) of 93.28% at 2 × 10−3 ppm at 298 K using the WL technique. The fluctuation in the kinetic and thermodynamic characteristics suggested that the PPTS was physically adsorbing to the MS, and its mixed-type inhibitive activity delayed both the cathodic as well as anodic processes following the Langmuir isotherm model. Furthermore, on the MS surface, the deposition of a highly protective layer was revealed by contact angle measurements. The implementation of quantum calculations (QC) and Monte Carlo simulation (MC) models produced insightful findings, and the outcomes were consistent with the outcomes of the experimental verdicts, indicating the possible corrosion inhibition characteristic of PPTS for MS in an HCl media.