Decoration of silver nanoparticles on activated graphite substrate and their electrocatalytic activity for methanol oxidation

Abstract

Abstract Silver nanoparticles (∼30–70 nm) have been impregnated on the activated graphite powder by an electroless plating method. The so prepared silver decorated graphite powders are characterized by field emission scanning electron microscopy, powder X-ray diffraction, energy dispersive X-ray and X-ray photoelectron spectroscopy. The activated graphite powder displays a high surface coverage with tin which is essential, as this ensures a thorough and complete coating of the graphite powder with silver. The electrochemical studies of Graphite, Sn/Graphite and successive decoration of Ag–Sn/Graphite powder have been carried out using cyclic voltammetry in the potential range between −1.2 and 0.0 V at a sweep rate of 50 mV s−1 and their electrocatalytic activity for methanol oxidation has been examined in alkaline medium. The effective active surface area of Graphite and Ag–Sn/Graphite electrode are calculated to be 6.2479 × 10−5 cm2 and 6.7886 × 10−5 cm2, respectively. The impedance spectrum of the Ag–Sn/Graphite electrode displays a depressed semicircle in the high-frequency region which corresponds to low charge resistance and high capacitance. The results highlight the electrocatalytic behavior of the graphite supported silver nanoparticles, making them suitable for fuel cell applications.