Two α-aminophosphonics acids as corrosion inhibitors for carbon steel in 0.5M HCl: Electrochemical and DFT/MD simulation.

Weight loss, potentiodynamic polarization spectroscopy (Tafel), and electrochemical impedance spectroscopy (EIS) were used to examine the effects of two alpha-aminophosphonic acids, namely (phenyl-phosphonomethylamino)-methyl) phosphonic acid (PHAP) and (propyl-phosphonomethyl-amino)-methyl) phosphonic acid (PRAP), on the surface of carbon steel. At 10-3 M, PHAP and PRAP had maximum efficiencies of 81.58 and 70.21 %, respectively. The topographies of the uninhibited and inhibited surfaces were measured using atomic force microscopy (AFM) and scanning electron microscopy (SEM). The Langmuir adsorption isotherm was followed by the inhibitors' adsorption on the carbon steel surface, and the kinetic parameters (Kads, Delta G degrees ads, Delta H degrees ads, and Delta S degrees ads) were determined for temperatures between 25 and 55 degrees C. Density functional theory (DFT) was used to compute the quantum chemical parameters using the (B3LYP) method and the 6-31 G (p, d) basis set. Utilizing molecular dynamics simulations (MDS), the interfacial arrangement of the produced chemicals and Fe(110)/H2O was identified. These theoretical discoveries strongly support the results of experiments.

Automated summary

This study examined the effects of two alpha-aminophosphonic acids on the surface of carbon steel using weight loss, potentiodynamic polarization spectroscopy, and electrochemical impedance spectroscopy. The results showed that these acids had good inhibitory effects on the corrosion of carbon steel at a certain concentration. The morphological changes of the inhibited and uninhibited surfaces were observed using atomic force microscopy and scanning electron microscopy, which were consistent with the experimental results. Density functional theory was used to calculate the quantum chemical parameters, and molecular dynamics simulations were performed to study the interfacial arrangement of the chemicals and Fe(110)/H2O. The theoretical findings strongly supported the experimental results.