Preparation Of Graphene-based Aerogels For CO₂ Adsorption

CO2 as a greenhouse gas in the primary gas, the adsorption of CO2 becomes particularly important, in order to obtain a high specific surface area and porosity developed CO2 adsorption material. In this paper, the biopolymer matrix with graphene, changing the mass ratio of polymer/graphene, obtained a series of polyme/graphene-based aerogels by gel method. Through nitrogen adsorption-desorption tests to analyze the pore structure, and explore the CO2 adsorption properties by CO2 adsorption test.The main contents and conclusions,(1) Chitosan and graphene oxide matrix, changing the mass ratio of chitosan/ oxidized graphene, prepared a series of chitosan/oxidized graphene-based aerogels by sol-gel method. Adsorption and desorption test of N2 concluded that when the mass ratio was 1:10 of chitosan/oxidized graphene, resulting chitosan/graphene oxide airgel group reached a specific surface area to 194 m2/g, the total pore volume and average pore diameter were 0.137 cm3/g and 2.8 nm.(2) In cyclodextrin with graphene oxide matrix, changing the mass ratio of cyclodextrin/graphene oxide by hydrothermal synthesis got a series of chitosan/ oxidized graphene-based airgel. Through experiments it can be concluded, cyclodextrin/graphene oxide mass ratio of 1:0.5, get chitosan/oxidized graphene-based airgel specific surface area reached 536 m2/g, CO2 adsorption capacity was 59 mg/g, the total pore volume and average pore diameter were 0.221 cm3/g and 5.6 nm. Different kinds of gas adsorption quantity test showed that CO2 adsorption quantity reached 59 mg/g, CH4 adsorption quantity reached 7.3 mg/g, H2 adsorption quantity reached 5.0 mg/g.(3) Glucose and graphene oxide matrix, changing the mass ratio of glucose/ graphene oxide prepared a series of glucose/graphene oxide airgel grouby hydrothermal synthesisp. The conclusion is that when the mass ratio got to 1:2 of glucose/graphene oxide, result to glucose/graphene oxide airgel group reached a specific surface area 530 m2/g, and CO2 adsorption capacity was 50 mg/g, the total pore volume and average pore diameter were 0.221 cm3/g and 15.5 nm. Different kinds of gas adsorption quantity test showed that CO2 adsorption quantity reached 50mg/g, CH4 adsorption quantity reached 12.2 mg/g, H2 adsorption quantity reached 11.3 mg/g.Finally activated glucose/graphene composite airgels at high temperature, then obtained a porous carbon material.The result is that when the mass ratio got to 1:2 of glucose/graphene oxide, obtained the activated porous carbon material that the specific surface area reached 763 m2/g, CO2 adsorption capacity reached to 79 mg/ g, the total pore volume and average pore diameter were 0.319 cm3/g and 16 nm. Different kinds of gas adsorption quantity test showed that CO2 adsorption quantity reached 76mg/g, CH4 adsorption quantity reached 16.9 mg/g, H2 adsorption quantity reached 11.8 mg/g. The increased specific surface area and pore volume result to adsorption of various gases increased.Throughout the text, using different polymers with the graphene composite obtained composite airgels. By changing the content of the polymer material, pore structure and adsorption properties of the composite airgels are changed, thereby increasing the CO2 adsorption properties.