Synthesis of silver nanoparticles on carbon papers for electrochemical catalysts

Abstract

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 0–0.5V vs. saturated calomel electrode (SCE) in 1M NaOH. According to the Randles–Sevcik plot, the diffusion coefficient under voltammetric regime ranges from 9.06×10−10 to 3.33×10−10cm2s−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.