▎ 摘　　要

NOVELTY - Method for improving self-supporting nitrogen-doped porous graphene for supercapacitors by mixing nano nickel powder, nano-aluminum powder and nano-copper powder, dispersing in dopamine/tris(hydroxymethyl)aminomethane-hydrochloric acid buffer solution, shaking, stirring the reaction at normal temperature and heating to obtain sheet-like nitrogen-doped porous graphene precursor, using polydopamine in the sheet-shaped nitrogen-doped porous graphene precursor as the solid precursor, nickel, aluminum and copper as catalysts and templates, sintering at high temperature in an inert gas sintering furnace and cooling to normal temperature in an inert gas to obtain nickel-aluminum-copper sheet coated with nitrogen-doped graphene products and placing the nickel-aluminum-copper sheet coated with the nitrogen-doped graphene product in a strong acid, repeatedly washing and drying in ultrapure water to obtain the product. USE - Method for improving self-supporting nitrogen-doped porous graphene for supercapacitors (claimed). ADVANTAGE - The method is simple, feasible, easy to control, economical and easy to popularize, has less risk, is suitable for mass-production on a large scale, ensures the porosity of graphene to obtain high-quality nitrogen-doped graphene and achieves thickness of the obtained nitrogen-doped graphene material of about 812 layers, nitrogen content of more than 15%, and specific surface area of more than 1800 m2/g. DETAILED DESCRIPTION - Method for improving self-supporting nitrogen-doped porous graphene for supercapacitors by (i) mixing the 12-15 g nano nickel powder, 5-8 g nano-aluminum powder and 10-12 g nano-copper powder, sequentially dispersing in 1500-2000 ml dopamine/tris(hydroxymethyl)aminomethane-hydrochloric acid buffer solution with a concentration of 6-8 mg/ml, and ultrasonically shaking for 2 hours, mechanically stirring the reaction at normal temperature for 3-4 hours, heating at 60 degrees C for 2-3 hours, and when it becomes a paste, pressing it into a sheet with a roller with a diameter of 45 cm to obtain sheet-like nitrogen-doped porous graphene precursor, (ii) using polydopamine in the sheet-shaped nitrogen-doped porous graphene precursor prepared in the step (i) as the solid precursor, nickel, aluminum and copper as catalysts and templates, sintering at a high temperature in an inert gas sintering furnace at 1100-1300 degrees C, and finally cooling to normal temperature in an inert gas to obtain nickel-aluminum-copper sheet coated with nitrogen-doped graphene products and (iii) placing the nickel-aluminum-copper sheet coated with nitrogen-doped graphene product prepared in step (ii) into a strong acid, where the nano-nickel-aluminum-copper powder template is etched away with the acid, repeatedly washing and drying in ultrapure water to obtain the product.