▎ 摘　　要

NOVELTY - A water-soluble cobalt salt, graphene oxide, urea and a surfactant are dispersed in water, to form a mixture containing 0.01-1 mmol/L water-soluble cobalt salt, 1-100 mg/L graphene oxide, 5-80 g/L urea and 5-30 g/L surfactant. The mixture is heated and reacted, to obtain a precursor. The precursor is calcined, to obtain nitrogen-doped graphene-cobalt oxide composite material. USE - Preparation of nitrogen-doped graphene-cobalt oxide composite material used for forming modified glassy carbon electrode and electrochemical sensor for detecting hydrogen peroxide (all claimed). ADVANTAGE - The method enables economical and quick preparation of nitrogen-doped graphene-cobalt oxide composite material, with high yield. The electrochemical sensor formed using the nitrogen-doped graphene-cobalt oxide composite material has excellent anti-interference ability and low detection limits. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for usage of nitrogen-doped graphene-cobalt oxide composite material for forming modified glassy carbon electrode, which involves dissolving nitrogen-doped graphene-cobalt oxide composite material and alcohol solvent in water, wet-coating and drying material.