ELECTROCHEMICAL INVESTIGATION OF INHIBITORY OF NEW SYNTHESIZED TETRAZOLE DERIVATIVE ON CORROSION OF STAINLESS STEEL 316L IN ACIDIC MEDIUM

Abstract

In this study, an  organic compound  inhibitor, namely N-benzyl-N-(4-chlorophenyl)-1H-tetrazole-5-amine (NBTA), was synthesized and the role of this inhibitor for corrosion protection of stainless steel (SS) exposed to 0.5 M H2SO4 was investigated using electrochemical, and quantum analysis. By taking advantage of potentiodynamic polarization, the inhibitory action of NBTA was found to be mainly mixed type with dominant anodic inhibition. The effectiveness of the inhibitor was also indicated using electrochemical impedance spectroscopy (EIS). Moreover, to provide further insight into the mechanism of inhibition, quantum chemical calculations of the inhibitor were performed. The adsorption of NBTA onto the SS surface followed the Langmuir adsorption model with the free energy of adsorption ΔG0ads of of -7.88 kJ mol-1. Quantum chemical calculations were employed to give further insight into the mechanism of inhibition action of NBTA.

Keywords

• organic inhibitor
• adsorption
• stainless steel
• impedance
• Density functional theory