Analysis of electrochemical impedance and XRD spectoscopy for complex self-assembled film on silver

摘要

Self-assembled monolayers (SAMs) of (3-mercaptopropy) trimethoxysilane (3-MPT) chemisorbed on silver surfaces were chemically 'modified by 1-octadecanethiol to form self-assembled mixed-monolayers (SAMM) and the co-polymer of N-vinylcarbazole and methyl methacrylate ester (to form complex self-assembled film (CSAF)). The oxidation resistance of these barriers on silver surfaces and some influential factors concerned processes were analyzed by electrochemical impedance spectroscopy (EIS) in a 10 percent NaOH aqueous solution at oxidation potential. X-ray diffraction (XRD) spectroscopy shows that the oxidation occurring on the silver surface may be restrained effectively due to the coating barrier, and CSAF(II) is the best one. Studies also reveal that oxide processes of bare silver and a series of modified silver electrodes in a 10 percent NaOH aqueous solution are of more than two relaxation time constants.