Composite material of nitrogen doped three-dimensional graphene supported nano silver and preparation method thereof

The invention provides a composite material of nitrogen doped three-dimensional graphene supported nano silver, wherein the composite material is a porous three-dimensional network structure which is formed by the self assembly of a graphene sheet with a nitrogen doping amount of 2.3 to 8.8% under the action of temperature and pressure; silver particles with a particle size of 80 to 120nm are evenly dispersed on the three-dimensional grapheme surface and the loading capacity of the composite material is 12 to 51%. The preparation method of the composite material comprises the following steps: taking graphite paper as an anode, a carbon rod as a cathode, concentrated sulfuric acid as electrolyte, performing oxidization and exfoliation, and preparing a thin layer graphene oxide material; and orderly adding ethanediamine and silver nitrate into graphene oxide suspension, performing an one step hydrothermal reaction, and then drying, thus the composite material is obtained. The preparation method of the composite