Dual Role of Polyaniline for Achieving Ag Dendrites and Enhancing Its Oxygen Reduction Reaction Catalytic Activity

Ag dendrites were readily achieved via the redox reaction between polyaniline and AgNO₃ in aqueous dispersion. The diffusion-limited aggregation was adopted for the generation of dendrite structure and the oxidized polyaniline was not removed for purifying the Ag dendrites. The existence of the Ag and polyaniline was confirmed by X-ray powder diffraction patterns and Fourier transform infrared spectra. The oxygen reduction reaction activity of the product was examined with rotating disk electrode voltammetry in 0.1 M KOH aqueous solution. The presence of the polyaniline greatly enhanced the oxygen reduction reaction catalytic activity of Ag dendrites and an onset and half-wave potential of 0.846 and 0.651 V vs. reversible hydrogen electrode, respectively, were obtained. We demonstrate the possible positive effect of the template that might be ignored in many cases and this can lead us to construct series of similar catalytic systems.