Copper (II) selective electrode based on chalcogenide materials: study of the membrane/solution interface with electrochemical impedance spectroscopy and X-ray photoelectron spectroscopy

The response of copper (II) ion-selective electrodes based on chalcogenide glassy–crystalline Cu–As–S alloys is described. The potentiometric measurements showed a Nernstian behavior in a large range of copper (II) concentration with short response time and a detection limit close to 1×10−6 M. The selectivity and the effect of the pH on the response have been determined. The chalcogenide membrane/solution interface has been investigated using electrochemical impedance spectroscopy (EIS) and X-ray photoelectron spectroscopy (XPS) in order to understand the sensing properties.