Experimental and theoretical investigation of phenyl disulphide as an effective inhibitor for copper in sodium chloride medium

Finding effective organic corrosion inhibitors is crucial for enhancing copper's corrosion inhibition performance in corrosive environments. This study focuses on the corrosion inhibition effect of Phenyl disulphide (PDF) on copper in 3.5 wt% NaCl solution. The results show that adding 2 mM PDF to NaCl solution decreased the corrosion current density from 6 mu A/cm2 to 1.1 mu A/cm2, with a corrosion efficiency of 81.7%. XPS analysis revealed that a protective S-Cu bonding layer was formed on the surface of copper, effectively restraining the corrosion process of copper. In addition, quantum chemistry calculations indicated that PDF was highly reactive and susceptible to electrophilic and nucleophilic attacks. The molecular dynamics simulation demonstrated that the molecule PDF adhered to the surface of Cu(111) in a parallel fashion. The binding energy was also calculated to be 235.8 kJ/mol, which effectively guarded the Cu surface and prevented contact with the Cl- containing corrosion medium.