▎ 摘　　要

NOVELTY - Cobalt-chromium-boron/nitrogen-doped graphene (Co-Cr-B/NGO) composite nanomaterials comprises nitrogen-doped graphene, soluble chromium salts and soluble cobalt salts, after the ultrasonic compounding is carried out in the ratio of a certain amount of substances, it is fully stirred. Then adding sodium borohydride solution for in situ reduction, freeze-drying the product obtained by reduction. USE - Cobalt-chromium-boron/nitrogen-doped graphene composite nanomaterials used as borohydride hydrolysis hydrogen production catalyst (claimed). ADVANTAGE - The preparation method is rapid, simple, energy-saving and environment-friendly, has good catalytic activity, and has good development prospect in the application field of hydrogen production by sodium borohydride hydrolysis. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for: a application of cobalt-chromium-boron/nitrogen-doped graphene (Co-Cr-B/NGO) composite nanomaterial as borohydride hydrolysis hydrogen production catalyst, having hydrogen liberation rate of catalytic borohydride water is 2000-3200 mol.mL-1.g-1, the hydrogen production rate is 100 wt.% and the activation energy Ea is 32-40 kJ.mol-1; and a method of preparing Co-Cr-B/NGO composite nanomaterial, which involves: i. weighing nitrogen-doped graphene, soluble chromium salts and soluble cobalt salts in a certain amount ratio, and then adding nitrogen-doped graphene, soluble chromium salts and soluble cobalt salts to deionized water and stirring and ultrasonic dispersion is carried out, finally, adding sodium borohydride for in-situ reduction, after the reaction is completed, filtering the above solution and washing to obtain the precursor; and ii. freezing the precursor obtained at -4 °C for 24 hours, and then freeze-drying at a certain temperature.