▎ 摘　　要

NOVELTY - A graphene-loaded cobalt tetraoxide nanocrystal composite material preparing method involves weighing graphene oxide and dispersing in de-ionized water ultrasonically to obtain oxidized graphene suspension, weighing cobalt salt solution and sodium salt solution, mixing and adding to the oxidized graphene suspension to obtain mixed solution. The mixed solution is added with aqueous ammonia and stirred to obtain complex solution. The complex solution is subjected to a hydrothermal treatment to obtain a black precipitate. The black precipitate is washed and dried to obtain the finished product. USE - Method for preparing graphene-loaded cobalt tetraoxide nanocrystal composite material for use as air cathode of zinc-air battery (claimed). ADVANTAGE - The method enables preparing graphene-loaded cobalt tetraoxide nanocrystal composite material with better industrial application value, in simple, convenient, eco-friendly and cost effective manner. DETAILED DESCRIPTION - A graphene-loaded cobalt tetraoxide nanocrystal composite material preparing method involves weighing graphene oxide and dispersing in de-ionized water ultrasonically to obtain oxidized graphene suspension, weighing cobalt salt solution and sodium salt solution, mixing evenly at room temperature and adding to the oxidized graphene suspension to obtain mixed solution. The mixed solution is added with aqueous ammonia and stirred uniformly to obtain a cobalt ammonia complex solution. The cobalt ammonia complex solution is subjected to a hydrothermal treatment under a sealed condition to obtain a black precipitate. The black precipitate is washed sequentially with deionized water and absolute ethanol and dried in air atmosphere to obtain the finished product.