▎ 摘　　要

NOVELTY - Silver-based composite material comprises 99-99.9 wt.% silver and 0.1-1 wt.% nitrogen-doped graphene, where amount of nitrogen elements in the nitrogen-doped graphene is 34.13-39.33 wt.%. USE - Used as silver-based composite material. ADVANTAGE - The material: improve the conductivity of the reduced graphene oxide, distribution of graphene in the matrix and the interface between graphene and the metal matrix. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for preparing silver-based composite material comprising (i) adding graphene oxide into deionized water, ultrasonically dispersing to obtain graphene oxide dispersion, (ii) adding urea into the graphene oxide dispersion to obtain a mixed solution A, ultrasonically dispersing the mixed solution A and magnetically stirring to obtain a mixed dispersion, (iii) mixing dispersion in the hydrothermal reaction kettle at 160 degrees C for 4-7 hours, removing, naturally cooling to room temperature, adding anhydrous ethanol A, washing, centrifuging and drying the precipitate obtained after centrifugation to obtain nitrogen-doped graphene powder, (iv) adding 0.1-1 wt.% nitrogen-doped graphene powder, 99-99.9 wt.% silver powder, dispersing nitrogen-doped graphene powder into anhydrous ethanol B, ultrasonicating for 30 minutes to obtain nitrogen-doped graphene anhydrous ethanol solution, dispersing silver powder into additional anhydrous ethanol C, ultrasonicating for 30 minutes to obtain silver-containing anhydrous ethanol solution, mixing nitrogen-doped graphene anhydrous ethanol solution and silver-containing anhydrous ethanol solution, ultrasonicating for 30 minutes, magnetically stirring at 60-80 degrees C and evaporating absolute ethanol to obtain composite powder, (v) subjecting composite powder to ball milling in a planetary ball mill, mixing the powder in the three-dimensional mixer to obtain mixed powder, and (vi) pressing mixed powder into a block, placing in a sintering furnace under nitrogen atmosphere, heating at 500-800 degrees C for 2-3 hours, pressure of 20-50 MPa to obtain silver-based composite material.