The influence of crystal faces on corrosion behavior of copper surface: First-principle and experiment study

When the MBT−:Cl− ratio is 50-10:1 in a solution containing of NaCl and Na-MBT (sodium salt of 2-mercaptobenzothiazole), the copper sample-1 (S1) was passivated; when the ration is 10-5:1, it was corroded. The copper sample-2 (S2) had no anti-corrosive ability in all solutions with MBT−:Cl− = 50-5:1. First-principle calculation revealed that the Cu atoms of (220) face, the main face of S1, have more unsaturated and energetic electrons than that of (200) and (111) faces, the main faces of S2. The highest chemical activation of the (220) face leads the S1 surface to show a better anti-corrosive ability.