Electroless Deposition of Silver Dendrite Nanostructure onto Glassy Carbon Electrode and Its Electrocatalytic Activity for Ascorbic Acid Oxidation

Well-defined silver dendrite nanostructures with primary and secondary branches on a glassy carbon electrode (GCE) surface are first demonstrated using a simple wet chemical electroless deposition method without any aid of a surfactant. The properties of dendrite structures were characterized using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS), cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS). Results of XPS and XRD indicated that most of the silver particles were not oxidized. The obtained silver dendrite GCE (Ag/GCE) showed high electrochemical activity toward catalytic oxidation for ascorbic acid (AA). The oxidation process followed a stepwise mechanism at slower scan rates (υ < 0.15 V s^-1) and a concerted mechanism at faster scan rates (υ > 0.15 V s^-1). The silver nanostructures are stable on the GCE surface and could be employed as an anode for an AA fuel cell.