▎ 摘　　要

NOVELTY - Preparation of the nitrogen-doped nano-cobalt sulfide/graphene photocatalytic material involves (i) dispersing 0.1-1 g graphene oxide in a mixed solution of 10-100 ml deionized water and ethanol, (ii) dissolving an appropriate amount of soluble cobalt salt in deionized water, (iii) dissolving an appropriate amount of 2-methylimidazole in deionized water, (iv) mixing the solutions obtained in the steps (i), (ii), and (iii), ultrasonically dispersing for 10-60 minutes, magnetically stirring the reaction and centrifuging the resulting product, and (v) adding the above-prepared ZIF-67 graphene oxide composite into the high temperature zone of the dual temperature zone tube furnace, locating the sulfur powder on the upstream of ZIF-67 graphene oxide compound, passing nitrogen as carrier gas and protective gas at the same time, and naturally cooling down to the room temperature. The mass ratio of cobalt sulfide and graphene in the obtained photocatalytic material is 1:5-5:1. USE - Preparation of nitrogen-doped nano-cobalt sulfide/graphene photocatalytic material used for photocatalytic degradation of organic pollutants e.g. rhodamine B and methylene blue (all claimed). DETAILED DESCRIPTION - Preparation of nitrogen-doped nano-cobalt sulfide/graphene photocatalytic material involves (i) dispersing 0.1-1 g graphene oxide in a mixed solution of 10-100 ml deionized water and ethanol and ultrasonically dispersing for 10-60 minutes to obtain a uniformly dispersed graphene oxide dispersion, (ii) dissolving an appropriate amount of soluble cobalt salt in deionized water, stirring and dissolving to obtain a 0.1-0.5 mol/L cobalt salt solution, (iii) dissolving an appropriate amount of 2-methylimidazole in deionized water, stirring and dissolving to obtain 0.5-2mol/L 2-methylimidazole solution, (iv) mixing the solutions obtained in the steps (i), (ii) and (iii), ultrasonically dispersing for 10-60 minutes, magnetically stirring the reaction at 30-60 degrees C for 4-8 hours, centrifuging the resulting product, washing with deionized water and ethanol several times and drying to obtain ZIF-67 graphene oxide composite, and (v) adding the above-prepared ZIF-67 graphene oxide composite into the high temperature zone of the dual temperature zone tube furnace, putting a porcelain boat containing 0.5-3 g sulfur powder into the low temperature zone of the above-mentioned dual-temperature zone tube furnace, locating the sulfur powder on the upstream of ZIF-67 graphene oxide compound, passing nitrogen as carrier gas and protective gas at the same time, controlling the temperature in the high temperature zone at 400-600 degrees C and low temperature zone at 100-200 degrees C, carrying out the vulcanization of the metal cobalt and the charring decomposition of the ligand, reacting for 1-3 hours and naturally cooling down to the room temperature. The mass ratio of cobalt sulfide and graphene in the obtained photocatalytic material is 1:5-5:1. The molar ratio of cobalt salt to 2-methylimidazole in the mixture is 1:2-4. An INDEPENDENT CLAIM is included for application of nitrogen-doped nano-cobalt sulfide/graphene photocatalytic material, which is used to degrade the organic pollutants under visible light.