▎ 摘　　要

NOVELTY - Preparation of organic dye-modified carbonitride graphene composite material includes mixing graphitic carbon nitride (g-C3N4) powder and alkaline aqueous solution, ball milling, filtering, adding precipitate to acidic aqueous solution, stirring, centrifuging, washing, and freeze-drying; adding first organic alcohol, adding with graphene alcohol solution, sonicating, heating, centrifuging, and vacuum-drying precipitate to obtain composite material; and adding with organic dye and third organic alcohol, sonicating, centrifuging, and washing precipitate. USE - Method for preparation of organic dye-modified carbonitride graphene composite material used for catalytic synthesis of methanol (claimed). ADVANTAGE - The product has mesoporous structure, higher specific surface, improved hole-charge separation rate and light absorption rate and utilization, water vapor and carbon dioxide reduction in visible light, and good photocatalytic performance of more than 8 times. DETAILED DESCRIPTION - Preparation of organic dye-modified carbonitride graphene composite material comprises: (A) mixing graphitic carbon nitride (g-C3N4) powder and alkaline aqueous solution, ball milling at speed of 100-600 revolutions/minute, filtering, adding precipitate to acidic aqueous solution, magnetically stirring at 25-90 degrees C to remove iron impurities, centrifuging, repeatedly washing with deionized water until washing pH is 6-7, and freeze-drying; (B) adding first organic alcohol to obtain first organic alcohol solution, mixing graphene with second organic alcohol to obtain graphene alcohol solution, adding to first organic alcohol solution, sonicating at speed of 1000-4000 Hz, heating to 100-240 degrees C for 8-24 hours, centrifuging, and vacuum-drying precipitate to obtain composite material; and (C) adding with organic dye and third organic alcohol, sonicating at speed of 1000-4000 Hz, centrifuging, and washing precipitate with third organic alcohol. The alkaline aqueous solution is sodium hydroxide aqueous solution or potassium hydroxide aqueous solution. The first, second and third organic alcohols are methanol, ethanol or propanol. The g-C3N4 and graphene have mass ratio of 1:0.01-0.4. The composite material and organic dye have mass ratio of 1:0.005~0.02. The third organic alcohol has dosage of 200-600 mL/g. An INDEPENDENT CLAIM is included for catalytic synthesis of methanol comprising adding organic dye-modified carbonitride graphene composite material and deionized water into reaction kettle of photocatalytic reaction device, purging with carbon dioxide at 60-100 degrees C and at 1-6 MPa for 3-5 hours, and illuminating at 105 mW/cm2 for 4 hours using 500 W xenon lamp as light source.