Some prepared schiff-base complexes for corrosion inhibition of steel in hydrochloric acid solution

This research investigates the use of organometallic chelates as new anticorrosion inhibitors for steel in harsh hydrochloric acid (HCl) conditions. The focus is on developing Schiff base complexes with Ag(I), Hg(II), and Sn(II) to protect steel surfaces. Various analytical methods, including elemental and spectral studies, molar conductance, magnetic moment, XRD, and SEM, confirmed the composition and nanostructure of the complexes. The thermal stability and degradation of the complexes are demonstrated using TGA/DTG analysis. FT-IR studies revealed that the Schiff base ligand binds to metal ions using imine (-CNH) and carboxylate (–COO–) groups. The complexes that were examined shown considerable effectiveness in preventing corrosion. Specifically, the Sn(II) chelates displayed a very high inhibition efficiency (IE %) of 94.21 % at a concentration of 1 ✕ 10−3 M at a temperature of 303 K, as determined using the Potentiodynamic polarization (PDP) approach. This adsorption process had a mixed-type inhibitory impact, causing delays in both the cathodic and anodic processes. These findings align with the Langmuir isotherm model. The application of quantum calculations (QC) models yielded valuable insights that were consistent with experimental findings, suggesting the potential of the material to limit corrosion. [Display omitted] •Thermal investigations and various spectroscopic methods have confirmed the formation of Schiff base complexes with silver(I), mercury (II), and tin (II).•A comprehensive study has been conducted to elucidate the adsorption behavior of the complexes as a corrosion inhibitors on steel.•PDP analysis indicated that the complexes act as mixed-type inhibitors.•DFT calculations identified relevant adsorption centers, providing molecular details regarding geometry and adsorption energy.