Structural characterization of a Cu(II) thin-film aging in a Cu-nitrate solution

The response of thin-film copper (II) ion-selective electrodes based on chalcogenide glassy Cu–Sb–Ge–Se is described according to the soaking time in a 10−4 M copper (II) solution. The chalcogenide membrane/solution interface has been investigated by using electrochemical impedance spectroscopy (EIS) and X-ray photoelectron spectroscopy (XPS) in order to understand the sensing properties. During the first month of the soaking, an alteration of the membrane by a chemical change without alteration of the sensor detection performance has been observed.