Synthesis and Application of Ag-Cu Bimetallic Dendrites

Abstract

We synthesized silver-copper (Ag-Cu) dendritic structures on Cu foil by electrodeposition and subsequent galvanic displacement reaction. The crystalline nature and morphology of the nanostructures were examined by X-ray diffraction (XRD) and field-emission scanning electron microscopy (FE-SEM), respectively. The morphology of the Cu precursor changed from rod to dendrite, and finally grew into foam as the overpotential was increased. When the Cu precursor was reacted with silver nitrate through galvanic displacement reaction, a foam-like precursor produced a denser, more uniform Ag-Cu dendrite. In addition, the concentration of silver nitrate solution had a considerable effect on the shape of the nanoparticles, with increasing concentration within a certain range promoting dendrite formation. The electrochemical properties of the Ag-Cu dendrite-modified electrode were characterized by linear sweep voltammetry and amperometric current-time curves. The reduction peak potential was about-0.25 V (vs a saturated calomel electrode (SCE)) in the electrolyte solution, which indicates that the as-synthesized Ag-Cu dendrites have favorable electroreduction activity towards hydrogen peroxide (H2O2). When an Ag-Cu dendrite was used as a sensor, the electrode exhibited a rapid response time of 3 s, a wide linear range of