▎ 摘　　要

NOVELTY - Preparation of three-dimensional hierarchical porous nitrogen-doped graphene involves washing porous biomass material, soaking in ethanol solution and carbonizing in tube furnace under inert atmosphere for 1-2 hours; placing in concentrated sulfuric acid, stirring in water bath for 20-40 minutes, adding excess solid potassium carbonate, stirring for 20-40 minutes and drying; activation treating in tube furnace under inert atmosphere at 600-900 degrees C for 1-3 hours; grinding, pickling, filtering and adding water until neutral; and freeze-drying. USE - Method for preparing three-dimensional hierarchical porous nitrogen-doped graphene (claimed). ADVANTAGE - The method is simple with excellent performance and good oxygen reduction activity graphene product. DETAILED DESCRIPTION - Preparation of three-dimensional hierarchical porous nitrogen-doped graphene comprises washing porous biomass material, soaking in ethanol solution and carbonizing in tube furnace under inert atmosphere for 1-2 hours; placing in concentrated sulfuric acid, adding to solid sodium nitrate and solid potassium permanganate, stirring in water bath for 20-40 minutes, adding excess solid potassium carbonate, stirring for 20-40 minutes and drying; activation treating in tube furnace under inert atmosphere at 600-900 degrees C for 1-3 hours; grinding, pickling using 0.5 mol/L sulfuric acid at room temperature for 4-8 hours, filtering and adding water until neutral; and freeze-drying.