Synthesis of a silver nanoparticle ink for fabrication of reference electrodes

Abstract

The silver nanoparticle (AgNP) ink synthesized was simple, well-dispersed, did not need sintering, had excellent conductivity and can be used as a conductive ink in several areas, particularly in the fabrication of reference electrodes. The AgNP ink was fabricated by synthesizing AgNP using the polyol method and then dispersing in methanol to fabricate the conductive ink. The synthesis was explained step-by-step, the proposed mechanism was discussed and photos of the entire process were shown. The materials (AgNO3 and AgNP) were characterized by UV–Vis, SEM and XRD. The UV–Vis exhibit a strong broad peak at 417 nm due the surface plasmon resonance (SPR) absorption band of AgNP. The SEM images showed spherical nanoparticles, non-aggregates and with an average diameter of 50 - 140 nm. The XRD of AgNP presented four main characteristic peaks for silver corresponding to (111), (200), (220) and (311) planes, confirming the cubic (FCC) silver. The AgNP ink has an excellent conductivity, with an average ohmic resistance of 1.53 Ω. Finally, the AgNP ink was tested in the fabrication of reference electrodes and the analytical response was higher than the conventional Ag/AgCl reference electrode.