Open AccessAdsorption of 2-mercaptobenzimidazole Corrosion Inhibitor on Copper: DFT Study on Model Oxidized Interfaces
Author(s) -
Fatah Chiter,
Dominique Costa,
Vincent Maurice,
Philippe Marcus
Publication year - 2020
Publication title -
journal of the electrochemical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.258
H-Index - 271
eISSN - 1945-7111
pISSN - 0013-4651
DOI - 10.1149/1945-7111/abcd4f
Subject(s) - adsorption , chemistry , copper , molecule , moiety , monolayer , aqueous solution , corrosion , inorganic chemistry , crystallography , computational chemistry , stereochemistry , organic chemistry , biochemistry
High corrosion inhibition efficiency of the 2-mercaptobenzimidazole (MBI) molecule for copper in different aqueous solutions is well established. We propose a first principle DFT study of the surface chemistry of the adsorption of MBI on preoxidized Cu(111). For both thione (MBIH) and thiolate (MBI ◦ ) species, the formation of a full monolayer (ML) is favored over low coverage adsorption. At the ML coverage, the molecules adopt a perpendicular orientation with respect to the surface. MBI ◦ interaction with the surface is stronger than MBIH one. MBIH and MBI ◦ bond to the surface forming a S–Cu bond; for MBIH, the NH moiety forms a H-bond with a surface oxygen atom; for MBI ◦ , a N–Cu bond is formed. For MBI ◦ at low coverage, a Cu–C bond is also formed. The charge analyses show a charge transfer between the surface and the molecule. Comparing the MBIH/MBI ◦ adsorption energies with that of water/OH, we find that MBI ◦ can replace H 2 O and OH at the preoxidized Cu surface. The results are compared with those obtained with 2-mercaptobenzothiazole, a similar azole derivative with corrosion inhibition properties.