Experimental and theoretical studies on inhibition performance of Cu corrosion in 0.5 M H2SO4 by three disulfide derivatives

Phenyl disulfide (PDF), 2,2'-dithiodipyridine (DDP), 5,5-dithiobis(1-phenyl-1H-tetrazole) (DPT) were studied as inhibitors for Cu in H2SO4 via electrochemical methods, surface morphology analysis and theoretical calculations. Electrochemical experiments show that PDF, DDP and OPT can exhibit excellent corrosion inhibition performance. Their order of corrosion inhibition is OPT > DDP > PDF. Surface morphology analysis supports the electrochemical results. The X-ray photoelectron spectroscopy (XPS) results show that S-Cu bonds are detected in PDF, DDP and OPT, and N-Cu bonds are detected in DDP and DPT. PDF, DDP and DPT adsorption on the Cu surface obey the Langmuir isotherm model. The results of quantum chemical calculations show that DPT has more active reaction sites than DDP and PDF. Molecular dynamics simulation results show that the order of binding energies of the three corrosion inhibitor molecules on the copper surface is DPT > DDP> PDF. (C) 2019 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.