Synthesis of silver nanoparticles on carbon papers for electrochemical catalysts

This article reports two routes, microwave-assisted synthesis and thermal reduction, to deposit silver nanoparticles on oxidized carbon paper (CP) electrodes. In comparison, as-grown Ag particles, prepared by the microwave-assisted route, exhibit uniform particle size and well-dispersion over the CP substrate. Electrochemical behavior of Ag-CP electrodes is characterized by cyclic voltammetry and AC impedance spectroscopy, incorporated with equivalent circuit. Both the catalyst electrodes display redox reversibility within the potential region of 0-0.5 V vs. saturated calomel electrode (SCE) in 1 M NaOH. According to the Randles-Sevcik plot, the diffusion coefficient under voltammetric regime ranges from 9.06 × 10^-10 to 3.33 × 10^-10 cm² s^-1. These differences of diffusion coefficient and capacitance are ascribed to the resulting Ag nanocatalysts with small particle size and no aggregation. On the basis of the results, the microwave-assisted approach for depositing nano sized Ag catalysts on CP electrodes shows the potential in application of alkaline fuel cells because of its fast synthesis, high activity, and simplicity.