Tof-Sims, Xps and Dft Study of the Adsorption of 2-Mercaptobenzothiazole on Copper in Neutral Aqueous Solution and Corrosion Protection in Chloride Solution

Abstract

X-ray photoelectron spectroscopy and time-of-flight secondary ions mass spectrometry analyses were performed to characterize the interaction of Cu with mercaptobenzothiazole (MBT) in aqueous solution without and with NaCl. Cu is covered by a Cu2O oxide layer whose thickness increases with exposure time in the absence of MBT. MBT forms multilayers on Cu oxide and inhibits the oxide layer growth.  The first MBT layer is strongly bonded to the surface through both S atoms. MBT adsorption inhibits Cl adsorption. Inductively Coupled Plasma Optical Emission Spectrophotometry experiments demonstrate that MBT adsorption inhibits Cu dissolution, even after 20 days immersion in NaCl.

Keywords: copper, 2-mercaptobenzothiazole, corrosion inhibition, XPS, TOF-SIMS, DFT