▎ 摘　　要

NOVELTY - Preparing three-dimensional nitrogen-doped graphene comprises mixing poly(2,5-benzimidazole) (ABPBI) solution and template agent nano-silicon dioxide, evaporating to dryness, carrying out pyrolysis under the protection of argon gas shield, removing the template agent and preparing three-dimensional nitrogen-doped graphene, where the poly(2,5-benzimidazole) is in soluble form, the polymer chain comprises aromatic rigid benzimidazole, and the molecules contain nitrogen-rich imidazole ring and terminal amino groups. USE - The graphene is useful as catalytic oxygen reduction reaction catalyst; in metal air battery and fuel cell; for catalyzing and electrolyzing water for oxygen evolution; and as electrode material for super capacitor (all claimed); and for electrochemical energy storage and conversion devices. DETAILED DESCRIPTION - Preparing three-dimensional nitrogen-doped graphene comprises mixing poly(2,5-benzimidazole) (ABPBI) solution and template agent nano-silicon dioxide, evaporating to dryness, carrying out pyrolysis under the protection of argon gas shield, removing the template agent and preparing three-dimensional nitrogen-doped graphene, where the poly(2,5-benzimidazole) is in soluble form, the polymer chain comprises aromatic rigid benzimidazole, and the molecules contain nitrogen-rich imidazole ring and terminal amino groups, and when the carboxy group in the molecule is pyrolyzed, the deacidification plays a role in making holes. The method comprises mixing poly(2,5-benzimidazole) solution with different particle diameter of silicon dioxide template of different mass ratio, stirring and evaporating the solvent, vacuum drying, grinding, carrying out pyrolysis in a high temperature furnace under argon gas shield for 2 hours, cooling, taking out, washing by diluted hydrofluoric acid (removing template) and activating. An INDEPENDENT CLAIM is also included for the three-dimensional nitrogen-doped graphene prepared by the above method.