▎ 摘　　要

NOVELTY - Preparation of high nitrogen doped graphene light ferromagnetic material involves (1) adding graphene oxide in dilute nitric acid solution, centrifuging and adding de-ionized (DI) water to form precipitate; (2) repeating step (1) for 2-3 times, repeatedly adding DI water and then centrifuging to ensure that it does not contain other impurity; (3) diluting the cleaned graphene oxide at 60o?C for 3-8 hours, then vacuum freezing and drying to form fluffy graphene oxide; (4) doping fluffy graphene oxide by ammonia gas/melamine at specific temperature; and (5) natural cooling the graphene. USE - For preparation of high nitrogen doped graphene light ferromagnetic material (claimed) which is useful in magnetic recording, magnetic memory or magnetic switch. ADVANTAGE - The high nitrogen doped ferromagnetic material has density close to graphene; displays good iron magnetic performance more than the liquid nitrogen temperature; and is a good light ferromagnetic material. DETAILED DESCRIPTION - Preparation of high nitrogen doped graphene light ferromagnetic material involves: (1) adding 0.0001-0.01 mol/l of graphene oxide in dilute nitric acid solution, then centrifuging for 5000-30000 revolution per minute (rpm) and adding de-ionized water (DI) to obtain precipitate; (2) repeating the step (1) for 2-3 times at 10000-30000 rpm to obtain precipitate, repeatedly adding de-ionized water and then centrifuging for 5-10 times to ensure that it does not contain other impurity; (3) diluting 0.01-0.2 mg/ml of cleaned graphene oxide at 60o?C for 3-8 hours, vacuum freezing and drying for 5 hours, then keeping at 35o?C for 24-30 hours to ensure the drying and to obtain the fluffy graphene oxide; (4) adding fluffy graphene oxide in a sealed can to resist high temperature using ammonia gas or melamine for doping at one end and the other end inserted in water for absorbing the tail gas, where the graphene oxide and melamine is added in mass ratio of 1:2 to 1:1, at a flow rate of 5-30 torr and at 300-1000o?C, annealing for 0.5-5 hours; and (5) natural cooling the graphene to room temperature to obtain the black graphene doped with nitrogen.