▎ 摘　　要

NOVELTY - Preparing tricobalt tetroxide/nitrogen-doped graphene oxide material comprises mixing graphene oxide, nitrogen source, cobalt source and water to obtain a suspension, subjecting suspension to a hydrothermal reaction to obtain a precursor, directly freeze-drying precursor solution to obtain a precursor, sintering precursor to obtain cobalt tetraoxide/nitrogen-doped graphene oxide material. USE - The method is useful for preparing tricobalt tetroxide/nitrogen-doped graphene oxide material, which is useful as sodium ion battery cathode material (claimed). ADVANTAGE - The tricobalt tetroxide/nitrogen-doped graphene oxide material has high specific capacity, multiplying power performance and cycle stability.