Novel electroless plating of silver nanoparticles on graphene nanoplatelets and its application for highly conductive epoxy composites

Abstract With the aim to develop electrically conductive adhesives (ECAs) as alternatives for traditional lead-based or lead-free solders in electronic packaging, we report an outstanding enhancement of electrical conductivity of epoxy ECAs filled with silver nanoparticles (AgNP)-decorated graphene nanoplatelets (AgNP@GNP). In order to avoid the deterioration of the superior properties of GNP, the GNP is directly sensitized by Sn precursor without conventional harsh-conditioned graphene oxide (GO) preparation, followed by the decoration of AgNP on sensitized GNP. The structural and morphological properties of AgNP@GNP were characterized using XRD, TEM, Raman, and TGA. The excellent distribution of SnO2 and AgNP on GNP could be explained by the attractive force between protonated GNP (pH  +20 mV) and lone-paired stannous ions. The electrical conductivity of as-prepared AgNP@GNP (1.3 × 105 S/cm) was nearly 6500 times than that of pristine GNP. Moreover, the electrical conductivity of the 20 vol% AgNP@GNP/epoxy ECAs was almost 500 times higher than that of pristine GNP/epoxy and 27-fold higher than that of conventional AgNP@GO/epoxy ECA.