Surface-enhanced Raman scattering and cyclic voltammetry studies of synergetic effects in the corrosion inhibition of copper by polybenzimidazole and mercaptobenzimidazole at high temperature

The inhibition of copper corrosion by polybenzimidazole and mercaptobenzimidazole at room and high temperature was assessed by in situ surface-enhanced Raman scattering (SERS) and cyclic voltammetry (CV). It was found that a very compact protective layer, produced by immersion in polybenzimidazole and mercaptobenzimidazole mixture solutions, showed better anticorrosive performance than each single inhibitor component even at high temperatures. This synergetic effect of the two components was explained by the physico-chemical mechanism of corrosion inhibition of polymeric coatings. Meanwhile, the results implied that the SERS active substrate prepared by the HNO3 etching method was particularly useful for in situ characterization of many problems in high-temperature surface chemistry which otherwise could not be accomplished by the usual SERS active substrates.