The invention relates to a simple preparation method of Fe (
ferrous), Co (
cobalt) and N (
nitrogen) three-element co-
doping three-dimensional
graphene with catalytic synergistic effect. The preparation method comprises the following steps of enabling soluble fully-aromatic PBI (polybenzimidazole) to react with a
ferrous salt and
cobalt salt mixing solution; firstly, preparing a complex of PBI,
ferrous ions and
cobalt ions; adding a nanometer template agent into the reaction mixing liquid; regularly arranging the complex at the surface of the template agent; pyrolyzing, removing a template, and the like, so as to prepare the Fe-Co-N three-element co-
doping three-dimensional
graphene. The PBI is selected from fully-aromatic macromolecules, such as ABPBI and mPBI, and the
viscosity average molecular weigh is 20,000 to 40,000; the
molar ratio of ferrous salt and
cobalt salt is 1:2 to 2:1; the
mass ratio of PBI and ferrous salt and
cobalt salt mixture is 1:2 to 2:1; the template agent is selected from nanometer
magnesium oxide,
ferric oxide and
ferric hydroxide nanoparticles; the particle size of the template agent is 5 to 50nm; the
mass ratio of PBI and template agent is 3:1 to 1:3; the
pyrolysis temperature is 700 to 1000 DEG C; the Fe-Co-N three-element co-
doping three-dimensional
graphene can be applied to the fields of
redox reaction catalysts, fuel batteries,
metal air battery
redox catalysts, water
electrolysis separation catalysts, supercapacitors and the like.