▎ 摘　　要

NOVELTY - Photo-catalytic co-catalyst comprises cobalt nanoparticles and graphene doped with nitrogen, where the mass ratio of the cobalt nano particles and nitrogen doped graphite alkene is 100-150:1. USE - The photo-catalytic co-catalyst is useful for non-noble metal. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for preparing the co-catalyst comprising preparing the graphene oxide by a Hummers, ultrasonicating for 1-3 hours, 0.4-2 mg/ml, preparing graphene oxide aqueous suspension, adding cobalt(II) chloride solution, the concentration of the cobalt(II) chloride solution is 20-400 mg/ml, the volume ratio of the graphene oxide aqueous suspension and cobalt(II) chloride aqueous solution is 20-70:1, freezing and drying to form brown powder, adding into tubular furnace for 1-2 hours to form black powder in argon gas and ammonia gas atmosphere. The ratio of argon gas and ammonia gas is 3-10:0.5.