Electrochemical Investigation of Tetrazolium Violet as a Novel Copper Corrosion Inhibitor in an Acid Environment

Tetrazolium violet (TZV) is an important pharmaceutical intermediate for the preparation of various medicines, taking into account microbiological studies and TZV as a new inhibitor of heterocyclic compound. The corrosion inhibiting action of TZV for copper in 0.5 M H₂SO₄ solutions was assessed by potentiodynamic polarization and electrochemical impedance spectroscopy. The corroded copper surfaces were evaluated by scanning electron microscopy. Thereafter, the thermodynamics of TZV adsorption onto copper was computed and evaluated. As a result, the target TZV compound shows great corrosion inhibition performance to protect copper in sulfuric acid. Thermodynamic test results reveal that the Langmuir, Dhar-Flory-Huggins, and Bockris-Swinkels isotherm models provide a better description for the adsorption process of TZV on the metal surface. The calculated values of ΔG _ads ⁰ indicate a spontaneous adsorption process of TZV on the copper surface accompanied by two kinds of interactions, physical adsorption and chemisorption.