▎ 摘　　要

NOVELTY - Preparing nano carbon dioxide capture agent comprises e.g. (i) dissolving mineral soil and cationic surfactant respectively in the de-ionized water, adding it into reaction kettle, heating, stirring and adjusting pH to obtain organic modified mineral soil solution; (ii) dissolving the chitosan in acetic acid, adding into reaction kettle, stirring, dissolving, dropping cationic surfactant to dissolve and adjusting pH to obtain the modified chitosan solution; (iii) dropping modified chitosan solution under the stirring condition into the organic modified mineral soil solution, stirring, homogenizing, dispersing ultrasonically, adjusting the pH value, filtering, drying and grinding to nano level; and (iv) adding the graphene oxide into de-ionized water, stirring and dispersing, suction filtering, adding into nano level organic modified mineral soil loaded modified chitosan nano-powder into graphene oxide dispersion liquid, reacting, filtering, drying and grinding to nano-grade powder. USE - The nano carbon dioxide capture agent is useful as fertilizer or in fertilizer for enhancing plant photosynthesis (claimed). ADVANTAGE - The method: prepares capture agent with high photocatalytic effect which captures carbon dioxide in the polymerized air and enriches the leaf stems for crops to absorb and use thus enhances photosynthesis, inhibits photorespiration at night, synthesizes chlorophyll for crop growth, accumulates the three elements of carbon, hydrogen and oxygen necessary for crop growth and absorbs, synthesizes and transforms organic components e.g. nitrogen, phosphorus, and potassium in the soil, promotes the gestation, growth and maturity of crops to increase production and income and can be used for both facility crops and field crops. DETAILED DESCRIPTION - Preparing nano carbon dioxide capture agent comprises (i) dissolving the mineral soil and cationic surfactant respectively in the de-ionized water, adding it into the reaction kettle, heating, stirring and adjusting pH to obtain organic modified mineral soil solution, where the mass ratio of the mineral soil and cationic surfactant is 3:1-1:1; (ii) dissolving the chitosan in acetic acid, adding into the reaction kettle, stirring, dissolving, dropping cationic surfactant to dissolve completely and adjusting pH to obtain the modified chitosan solution, the mass ratio of the chitosan and the cationic surfactant is 9: 1-11:1; (iii) dropping the modified chitosan solution under the stirring condition into the organic modified mineral soil solution, stirring, homogenizing, dispersing ultrasonically, adjusting the pH value to obtain organic modified mineral soil load modified chitosan solution, filtering, drying and grinding to nano level, where the mass ratio of the modified chitosan solution and the organic modified mineral soil solution is 0.05-0.1; (iv) adding the graphene oxide into de-ionized water, stirring and dispersing to obtain graphene oxide dispersion liquid, suction filtering the organic modified mineral soil loaded modified chitosan solution to the nano level, adding the obtained organic modified mineral soil loaded modified chitosan nano-powder into the graphene oxide dispersion liquid, reacting in the reactor, filtering, drying and grinding to nano-grade powder to obtain organic modified mineral soil load modified chitosan and graphene oxide powder, where the mass ratio of the organic modified mineral soil-supported modified chitosan nano powder to the graphene oxide is 8:1-15:1; and (v) dispersing the hydrotalcite in de-ionized water to dissolve fully, adding nano-grade powder slowly, adjusting pH to precipitate in the mixed solution, stirring magnetically, homogenizing and dispersing to obtain nano carbon dioxide capture at mass ratio of the nano-powder to the hydrotalcite is 2:1-4:1