Evaluation of corrosion inhibition performance of tetrathiafulvalene derivatives for copper in NaCl solution: Electrochemical, morphological and computational approaches

Abstract

The protection ability of the synthesized tetrathiafulvalene derivative namely 4,4’(5’)- [Bis-(3-pyridinemethenyl)]-3,7 dimethyltetrathiafulvalene (TTF) as corrosion inhibitor of copper in 100 ppm NaCl was investigated through electrochemical, morphological, and computational methods. The obtained potentiodynamic polarization data revealed that the TTF act as an excellent mixed type corrosion inhibitor for copper in NaCl solution reached a maximum efficiency of 99.98% at 10 −3 M, and their adsorption obeys Langmuir adsorption isotherm. It was observed that the value of the standard adsorption free energy Δ G ads 0 35.53 kJ/mol, that signifying a mixed mode of adsorption. Electrochemical impedance study revealed that the TTF compound formed a thin protective film on the copper surface. The equivalent circuit was used to analyze the model of the corrosion inhibition process. Surface morphology examination by scanning electron microscopy (SEM), and atomic force microscope (AFM) confirmed the formation of a protective layer on the copper surface. Furthermore, quantum chemical calculations and molecular dynamics simulation were used to investigate the inhibition mechanism at the atomic level, the obtained results support the experimental results and confirm the excellent ability of the TTF compound to protect the copper from corrosion in NaCl medium.