Novel tetrazole-based symmetrical diselenides as corrosion inhibitors for N80 carbon steel in 1 M HCl solutions: Experimental and theoretical studies

Two new tetrazole-based symmetrical diselenide derivatives (TDS1 and TDS2) were synthesized via one-pot azido-Ugi reaction and in good yields. The inhibiting action of these compounds was further studied on the corrosion of N80 carbon steel in 1 M HCl using different techniques such as weight loss method, potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and electrochemical frequency modulation (EFM). Interestingly, TDS2 (50 ppm) manifested inhibition efficiency up to 93% and this was confirmed using different experimental techniques such as EIS and EFM. Potentiodynamic polarization measurements showed that the investigated compounds belong to mixed type inhibitors and they are working according to the Langmuir adsorption isotherm. Calculated quantum chemical parameters provided a theoretical rational for the adsorption and inhibition activities of TDS1 and TDS2 on N80 carbon steel corrosion inhibition. Moreover, TDS1 and TDS2 have been simulated as adsorbate on Fe (1 1 0) substrate and their relative adsorption energies were identified on iron surface and the quantum chemical calculation and molecular dynamics simulation were in agreement with the experimental observations. These results indicate that TDS1 and TDS2 are good corrosion inhibitors.