An Investigation into the Synthesis and Characterization of Novel Tetrazole Derivatives for Application as Mild Steel Corrosion Inhibitors in a Solution of Hydrochloric Acid

The objective of the study was to synthesize tetrazole molecules featuring nitro groups positioned at the para and meta locations. We aimed to assess their effectiveness in inhibiting corrosion of mild steel in a 1 M HCl solution at 298 K. Tetrazoles with 2,5-disubstitution were created using [3 + 2] cycloaddition and N-alkylation techniques, with a particular emphasis on synthesizing molecules that contain nitro groups. Tafel polarization experiments, which employ the polarization curve approach, were used to assess the effectiveness of corrosion inhibition. Furthermore, quantum chemical calculations using density functional theory and Monte Carlo simulations were used to investigate the connection between the molecular structure of the produced tetrazoles and their efficacy as corrosion inhibitors. The results showed that the 2,5-disubstituted tetrazoles exhibited high corrosion inhibition efficiencies, with compounds P1 and P2 achieving inhibition rates of 82.7 and 94.6%, respectively, at a concentration of 10–4 M. The Tafel polarization results confirmed the effectiveness of the synthesized tetrazoles, while the theoretical calculations supported the experimental outcomes, establishing a strong correlation between their molecular structure and corrosion inhibition performance.