Fabrication Of Hierarchical Carbon Nanosheet-based Materials And Research On Adsorption Of Carbon Dioxide

CO2 is the main component of green house gas.The capture of CO2 is of great significance.Adsorption is widely uesd in the industrial capture of CO2.Owning to wide obtaining sources and controllable surface,porous carbon adsorbent is attractive.Based on the background,in this paper,different novel graphene-based nanosheet carbon materials were prepared following with activation and impregnation by PEI to obtain CO2 adsorbents with high adsorption performance and excellent selectivity.Besides,the chemical process conditions were studied as well to realize the best adsorption properties.The main research is as follows:(1)Fabrication of hierarchical carbon nanosheet-based networks for adsorption of CO2Graphene-based nanosheet carbon materials with an annular space structure were prepared by using CTAB as a soft template,GO as a structure-directing agent,melamine as a binder,and phenolic resin as carbon source.The material has a well-developed pore structure,and the total specific surface area and total pore volume are 481.2 m2·g-1 and 0.94 cm3·g-1,respectively.The material can be physically adsorbed by CO2 at low temperature after activation by KOH.The adsorption capacity at 273 K reaches 4.62 mmol·g-1.The material can form a solid amine adsorbent by supporting PEI,which can be used for CO2 chemical adsorption at high temperature.The amount can reach 5.52 mmol·g-1,and the chemisorption process has rapid adsorption kinetics and can maintain stable adsorption performance during long-term circulation.(2)Preparation of mesoporous carbon-nanosheet materials by hard template method and research on adsorption properties of CO2Graphene-based mesoporous nanosheet carbon materials were prepared by using 1,6-hexanediamine as a linking agent,silica sol as a hard template and phenolic resin as a carbon source under the control of GO.The amount of hard templating agent added and the coating quality ratio all affect the surface morphology and pore structure properties of the material.The highest specific surface area and total pore volume of the material were 966.2 m2·g-1 and 2.57 cm3·g-1,respectively.The PEI is supported to form a solid amine adsorbent,which can be used in the chemical adsorption process at high temperature.The highest adsorption amount can reach 5.22 mmol·g-1,and the amine utilization rate at this time is 66.4%,showing good adsorption performance.