Adsorption of 2-Mercaptobenzothiazole Organic Inhibitor and its Effects on Copper Anodic Oxidation in Alkaline Environment

Abstract

The adsorption of 2-MBT organic inhibitor on copper and its effects on anodic oxide growth in NaOH were investigated using cyclic voltammetry, X-ray photoelectron spectroscopy, and time-of-flight secondary ion mass spectrometry techniques. It is shown that 2-MBT significantly impedes the growth of the Cu(I) oxide by forming a multilayered organic film on the surface. A major factor influencing the formation and properties of the organic barrier layer is the presence and structure of the interfacial native oxide on which it forms. The 2-MBT multilayer bonds to the metallic copper substrate mostly via its sulphur atoms along with a small fraction of the nitrogen atoms also bonding to the metallic substrate. Additionally, there is an interaction between the inhibitor molecules and copper released from the surface to form metal-organic complexes in the outer layers of the thicker films.