▎ 摘　　要

NOVELTY - The method for preparing three-dimensional nitrogen-doped graphene, involves mixing (2,5-benzimidazole) solution with magnesium oxide template, evaporating under argon protection, pyrolyzing, removing template to prepare final product. The polymer chain of poly (2,5 benzimidazole) is composed of aromatic rigid benzimidazole composition and molecules containing nitrogen-rich imidazole ring and terminal amino groups. The poly (2,5 benzimidazole) solution and magnesium oxide template with different particle size are mixed according to different mass ratio. USE - Method for preparing three-dimensional nitrogen-doped graphene for use as catalyst for catalytic oxygen reduction in metal air battery and fuel cell, and catalyst for catalytic electrolysis of water and oxygen precipitation reaction in electrode material of supercapacitor. DETAILED DESCRIPTION - Method for preparing three-dimensional nitrogen-doped graphene, involves mixing (2,5-benzimidazole) solution with magnesium oxide template, evaporating under argon protection, pyrolyzing, removing the template to prepare three-dimensional nitrogen-doped graphene. The polymer chain of poly (2,5 benzimidazole) is composed of aromatic rigid benzimidazole composition and molecules containing nitrogen-rich imidazole ring and terminal amino groups. The poly (2,5 benzimidazole) solution and magnesium oxide template with different particle size are mixed according to different mass ratio, so that the planar benzimidazole ring is regularly arranged on the surface of template, and the pyrolysis reaction is carried out to form nitrogen-doped graphene structure. The particle size, pyrolysis temperature, pore size, structure and other factors has an important impact on the formation of nitrogen-doped graphene layer. The three-dimensional nitrogen-doped graphene is used as catalyst for catalytic oxygen reduction in metal air battery and fuel cell, and catalyst for catalytic electrolysis of water and oxygen precipitation reaction in electrode material of supercapacitor.