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

[Display omitted] •Electrochemical test data indicate the order of inhibition efficiency: DPT > DDP > PDF.•The XPS results show that SCu bonds are generated in PDF, DDP and DPT, and NCu bonds are detected in DDP and DPT.•The DPT, DDP, and PDF adsorb on the Cu surface in accordance with the Langmuir model.•Quantum chemistry research and molecular dynamics simulation provide in-depth understanding of the experimental results. 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 DPT can exhibit excellent corrosion inhibition performance. Their order of corrosion inhibition is DPT > DDP > PDF. Surface morphology analysis supports the electrochemical results. The X-ray photoelectron spectroscopy (XPS) results show that SCu bonds are detected in PDF, DDP and DPT, and NCu 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.