化学还原法原位制备石墨烯/纳米银复合粉体及其导电性能

Nano-silver/graphene composite powders were prepared by chemical reduction method using hydrazine hydrate as reducing agent, PVP as dispersant, graphene oxide and silver nitrate as precursor at the reaction temperature of 60 ℃ and the pH of 6. The effects of silver nitrate concentration in solution on the morphology and structure of nano-silver/graphene composite powders were investigated by SEM, XRD, IR and RAMAN. Low temperature curing conductive silver paste was prepared by using graphene/nano-silver composite powder instead of some micron silver powder, and its conductive properties were studied. The results indicate that Ag nanoparticles uniformly distribute in the graphene sheets. Pherical silver particles with better dispersibility and uniform particle size can be obtained by using 0.75 g/L of silver nitrate, 0.25 g/L of graphene oxide. The size of Ag nanoparticles on the graphene sheets centralizes at 100 nm. When using graphene/nano-silver composite powder instead of 4% micron silver powder to prepare conductive paste, the volume resistivity of conductive paste is 1.8×10−5 Ω•cm. Compared with the conductive paste without graphene/nano-silver composite powder, the resistivity decreases by 61.7%.