▎ 摘　　要

NOVELTY - Hydrated ferric nitrate is added to solution of graphene, stirred, and separated precipitate is washed and dried under vacuum to obtain graphene/akaganeite-type nanocrystals. Hydrated ferric chloride soluble in water, is added to sodium nitrate, and graphene/akaganeite-type nanocrystals are added after dissolution. Obtained mixture is ultrasonically dispersed, and hydrothermally reacted. Precipitate is washed, dried and obtained graphene/akaganeite-type nanosheet array is annealed to obtain three-dimensional graphene/ gamma -ferric oxide magnetic nano array. USE - Manufacture of three-dimensional graphene/gamma-ferric oxide magnetic nano array (claimed). ADVANTAGE - The method efficiently provides lightweight three-dimensional graphene/gamma-ferric oxide magnetic nano array having large absorption frequency width. DETAILED DESCRIPTION - Hydrated ferric nitrate (Fe(NO3)3.9H2O) is added to solution of graphene, such that mass ratio of graphene and hydrated ferric nitrate is 1:100. The obtained mixed solution is stirred for two hours at 50 degrees C, and the precipitate is separated by centrifugation. The resultant product is then washed with distilled water and ethanol, and dried under vacuum to obtain graphene/akaganeite-type ( beta -FeO(OH)) nanocrystals. Hydrated ferric chloride (FeCl3.6?2O) (5 g) soluble in water, is added to sodium nitrate, and graphene/akaganeite-type nanocrystals (0.15 g) are added after dissolution. The obtained mixture is ultrasonically dispersed uniformly, and hydrothermal reaction is carried out by placing in an autoclave at 60 degrees C for 12 hours. The obtained precipitate is washed with distilled water and ethanol for several times, and dried in vacuum to obtain graphene/akaganeite-type nanosheet array. The dried nanosheet is heated at 300 degrees C, and annealed for two hours to obtain three-dimensional graphene/ gamma -ferric oxide magnetic nano array.