▎ 摘　　要

NOVELTY - Preparing nitrogen-doped graphene comprises e.g. (i) adding lime nitrogen, carbon source and deionized water separately into the beaker, heating the reaction material in a water bath while stirring, controlling the water bath temperature at 60-80 degrees C, introducing the carbon dioxide gas into the beaker to the pH of the reaction material to 9-12, reacting for 3-5 hours, uniformly spreading the reaction materials into the enamel pan, placing the enamel tray in a blast drying oven at 45-55 degrees C for 3.5-4.5 hours, and finally taking the dried material in the enamel tray and transferring into a mortar and grinding uniformly to obtain solid powder, where the mass ratio between the lime nitrogen, carbon source and the deionized water is (1-4):1:(2-20), (ii) transferring the solid powder obtained in the step (i) into a porcelain boat and placing in a tube furnace for pyrolysis, protecting the tube furnace by nitrogen gas, and heating the tube furnace. USE - The method is useful for preparing nitrogen-doped graphene. ADVANTAGE - The method: utilizes low cost lime nitrogen as raw material; and has no metal catalyst is needed during the preparation process; and reduces production cost. DETAILED DESCRIPTION - Preparing nitrogen-doped graphene comprises (i) adding lime nitrogen, carbon source and deionized water separately into the beaker, heating the reaction material in a water bath while stirring, controlling the water bath temperature at 60-80 degrees C, introducing the carbon dioxide gas into the beaker to the pH of the reaction material to 9-12, reacting for 3-5 hours, uniformly spreading the reaction materials into the enamel pan, placing the enamel tray in a blast drying oven at 45-55 degrees C for 3.5-4.5 hours, and finally taking the dried material in the enamel tray and transferring into a mortar and grinding uniformly to obtain solid powder, where the mass ratio between the lime nitrogen, carbon source and the deionized water is (1-4):1:(2-20), (ii) transferring the solid powder obtained in the step (i) into a porcelain boat and placing in a tube furnace for pyrolysis, protecting the tube furnace by nitrogen gas, first heating the tube furnace to temperature of 540-580 degrees C at rate of 1-3 degrees C/minutes, and maintaining the temperature for 2-3 hours, heating the temperature of 750-950 degrees C at rate of 3-8 degrees C/minutes, insulating for 1-2 hours, when the temperature in the furnace chamber is naturally cooling to room temperature, taking out the product, soaking the product in the dilute hydrochloric acid, washing and filtering, and washing with distilled water until neutral, drying the product at 75-85 degrees C for 3.5-4.5 hours to obtain nitrogen-doped graphene.