▎ 摘　　要

NOVELTY - Graphite oxide is added to distilled water and dispersed to obtain a graphene oxide yellow aqueous dispersion. Hydrazine hydrate solution and water are added to the dispersion, and heated to obtain a homogeneous mixed solution. The mixed solution is transferred to a stainless steel autoclave. The contents are hydrothermally reacted at 160-200 degrees C for 8-12 hours and then naturally cooled to room temperature. The reaction product is taken out, filtered, washed and vacuum-dried to obtain a black powder of nitrogen-doped graphene. USE - Preparation of nitrogen-doped graphene (claimed). ADVANTAGE - The method provides nitrogen-doped graphene having a nitrogen content of 3.9-5.7 wt.% and a carbon/oxygen ratio of 12-16%, with high yield. The method is simple and easy to be controlled, and consumes less energy. DETAILED DESCRIPTION - 3 g Graphite flakes, 3 g sodium nitrate, and 1.5 g concentrated sulfuric are mixed, and the mixture is cooled in an ice-water bath for 3 hours, temperature-increased to 0-20 degrees C, and added with 9 g potassium permanganate. The mixture is transferred to an oil bath, maintained at 35 degrees C, added with deionized water, and added with dilute hydrogen peroxide after 10 minutes to obtain a bright yellow solution. The solution is repeatedly washed with 10% hydrochloric acid and distilled water, filtered, and dialyzed. The obtained sticky solid is pH-adjusted close to neutral, dried, and ground to obtain graphite oxide. 60-140 mg Graphite oxide is added to 60-70 mL distilled water, and ultrasonically cleaned and dispersed for 2 hours to obtain a 1-2 mg/mL graphene oxide yellow aqueous dispersion. 1-2 mL Hydrazine hydrate solution and water are added to the graphene oxide dispersion, and magnetically heated and stirred for 10 minutes to obtain a homogeneous mixed solution. The volume ratio of graphene oxide dispersion and aqueous hydrazine hydrate solution is 30-70:1. The mixed solution is transferred to a stainless steel autoclave and filled to 70-80%. The contents are hydrothermally reacted at 160-200 degrees C for 8-12 hours and then naturally cooled to room temperature. The reaction product is taken out, filtered, washed thrice with distilled water, ethanol, and acetone, and vacuum-dried at 60 degrees C for 24 hours to obtain a black powder of nitrogen-doped graphene.