Study on corrosion inhibition properties of disulfide derivatives with different hydrophobicity in sulfuric acid

•A highly effective corrosion inhibitor for copper surfaces.•The corrosion inhibition mechanism was analyzed.•The chemical bond of corrosion inhibitor copper was confirmed by XPS. In this study, we systematically evaluated the corrosion inhibition efficacy of three dithio derivatives—dimethyl disulfide (DTD), dipropyl disulfide (DPD), and dihexyl disulfide (DHD) on copper in 0.5 M sulfuric acid. A comprehensive approach involving electrochemical techniques, morphological characterization, and theoretical calculations was employed to assess their protective efficiency and underlying mechanisms. The results indicated that all three inhibitors significantly mitigated copper corrosion, with their hydrophobicity, and consequently, their corrosion inhibition efficiency, increasing alongside the length of their carbon chains. A pronounced increase in corrosion inhibition efficiency (η) as the concentration of all three inhibitors rises can be seen. Their corrosion inhibition ability is DTD < DPD < DHD. The results of polarization curves indicate that the maximum corrosion inhibition efficiency (η) of DHD for Cu was close to 92.4%, when its concentration is 1 mM, suggesting the formation of a dense and ordered adsorption film on the copper surface. This observation is consistent with the electrochemical and morphological analysis, which confirmed the adsorptive behavior of the inhibitors and the presence of a protective layer. Theoretical calculations further substantiated the correlation between the molecular configuration and the corrosion inhibition performance, aligning with the experimental data. [Display omitted]