Photoelectrochemical sensor based on Au/ZnS/ZnO nanomaterials for selective detection of copper ions

Abstract

Composite electrodes of Au/ZnS/ZnO sensor were prepared by hydrothermal method and electrodeposition for photoelectrochemical (PEC) detection of copper(Cu2+) ions. Firstly, ZnO nanorods are made of nickel (Ni) foam, and then ZnS microspheres are grown on this basis, and then gold (Au) nanoparticles (NPs) are fixed on the surface to form an Au/ZnS/ZnO overall system. The electrochemical properties of Au/ZnS/ZnO materials were measured by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) in an aqueous solution of 1 M KOH. When the sensor detects Cu2+ ions, its photocurrent response can be improved. The detection response of Au/ZnS/ZnO electrode for Cu2+ ions is in the linear range of 0.1–10 μM, and its detection limit is 0.01 μM. The results show that the material has better stability and electrochemical performance for the detection of Cu2+ ions.