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The main focus of this work is a detailed electrochemical impedance spectroscopy (EIS) study at different potentials of an in situ-prepared antimony-film modified electrode (SbFE) in either 0.01 M HCl or 0.1 M acetate buffer solutions. No such detailed EIS study has been presented previously. First, method validation in terms of detection and quantification limits (LOD and LOQ respectively), linear concentration range, accuracy, and precision was performed for the bare glassy carbon electrode (GCE) and in situ-formed SbFE in both media employed in the determination of trace amounts of Zn(II), Cd(II), and Pb(II). Next, by means of EIS, the performance of these electrodes was explained by investigating the electrode's behavior at certain potentials that are crucial in anodic stripping voltammetry experiments. The method sensitivity was explained by the polarization resistance values obtained from the detailed EIS fitting procedure. Furthermore, a combination of charge-transfer-controlled and diffusion-controlled processes was taken into account. It was shown that the behavior of these electrodes strongly depends on the medium used, on the potential applied, and on the presence of certain species in the solution. Potentials of zero charge were also evaluated for the bare GCE and SbFEs in both solutions.

The influence of the benzotriazole (BTAH) inhibitor on the thickness of the oxide layer formed on Cu immersed in 3% NaCl solution was studied with angle-resolved X-ray photoelectron spectroscopy. The X-ray-induced Auger spectra were reconstructed with the Monte Carlo algorithm using the spectra of the basic constituents [Cu(I)BTA, , and Cu] formed on the surface. The relative contributions of the basic constituents to the composite spectra measured at different emission angles were then used to estimate the thickness of the oxide layer. The results show that the presence of BTAH substantially reduces the thickness of the oxide layer formed on Cu in chloride media. The average thickness of the layer below the Cu(I)BTA layer is estimated to be , whereas the thickness of the noninhibited sample is .

The surface chemistry of two corrosion inhibitors, 1-hydroxybenzotriazole (BTAOH) and benzotriazole (BTAH), adsorbed on copper from 3% NaCl aqueous solution, was investigated by X-ray photoelectron spectroscopy (XPS). Surface and subsurface chemical structure, composition, and layer thickness were obtained from angle-resolved XPS measurements, from detailed analysis of the background in the XPS spectra by the Tougaard method, and from XPS depth profiling performed by Ar-ion sputtering. The main concern was the shape of the X-ray induced Auger Cu spectrum that offers the possibility to investigate the Cu(I) environment. The Auger Cu spectrum obtained after treatment in the BTAH-containing solution was decomposed into three components originating from the Cu(I)BTA complex layer, the underlayer, and the Cu substrate. This procedure indicates the formation of the Cu(I)BTA surface complex on the underlayer after BTAH treatment. The BTAH molecules [either in the Cu(I)BTA complex or uncomplexed] are directed toward the Cu surface through their triazole N atoms. In contrast to the BTAH treatment, the Cu-BTAOH layer formed on the Cu surface after treatment in the BTAOH solution is less ordered and is much thinner than the Cu-BTAH structure.