▎ 摘　　要

NOVELTY - Method for preparing nitrogen-doped graphene involves adding graphite powder and sodium nitrate to concentrated sulfuric acid to form a first reaction system, adding potassium permanganate under stirring, heating at first predetermined temperature, continuing to stir for first predetermined time to form a second reaction system, adding deionized water, heating at a second predetermined temperature, continuing to stir for a second predetermined time to obtain a third reaction system, diluting with deionized water and adding hydrogen peroxide until no air bubble is formed to obtain a fourth reaction system, leaving still until delamination occurs, removing supernatant, washing lower precipitate, placing in a dialysis bag to dialyze to neutrality, drying dialysis product to obtain graphite oxide, dispersing in deionized water, adding urea or ammonium salt, mixing, freeze-drying, heating at 700-1000 degrees C, maintaining for 15-25 minutes, and cooling to room temperature to obtain the product. USE - The method is useful for preparing nitrogen-doped graphene. ADVANTAGE - The method is high in efficiency and environmentally-friendly.