A combined experimental and theoretical study of the inhibition effect of three disulfide-based flavouring agents for copper corrosion in 0.5 M sulfuric acid.

Diallyl disulfide (DAD), propyl disulfide (PPD) and dibenzyl disulfide (DBD) flavouring agents as copper corrosion inhibitors in 0.5 mol/L H2SO4 solution were evaluated with multitudinous experiments including electrochemical techniques, morphological characterization measurements, FTIR spectra and theoretical calculations. The electrochemical results indicate that PPD and DBD show mixed-type inhibitors and DAD belongs to cathodic-type inhibitor, and the corrosion inhibition capacity follow order: PPD > DBD > DAD. The adsorption of these compounds on the surface of copper conforms to the Langmuir adsorption isotherm model. Furthermore, theoretical calculations were applied to deeply understand the inhibition mechanism of three disulfide-based compounds.