Study Of Preparation And Adsorption Properties Of Mesoporous Carbons Via Sol-Gel Method

Activated carbon as porous matter is widely used in the fields such asfood, pharmacy, catalysis, adsorption and separation, and so on. Thecommercial activated carbon(AC) and activated carbon fiber(ACF) containmainlymicropore and cannot meet the demands of adsorption and separationof larger molecules, catalyst supports for larger molecule reaction and doublelayer capacitor etc. A efficient polymer chemical blend and carbonizationmethod, in which the source of silica template and the carbon precesor,weredissolved together, was brought out to prepare mesoporous carbon with ahighsurfaceareaandnarrowporesizedistribution.The influence of preparation conditions on the pore structure of carbonmixing the different source of carbon precursor, such as tetraethylorthosilicate (TEOS) as silica template was studied. Nitrogen adsorption is astandard tool for determination the porous structure parameters of poroussolids. We carried out extensive adsorption studies of a series of mesoporouscarbon. By the aid of nitrogen adsorption measurement at low temperature,the results show that the pore diameter of porous carbons obtained hasspecific surface and pore size taking sucrose andβ-cyclodextrin as thesourceofcarbonprecursor.Becausesucrosehasgoodwatersolubilityandlowprice, wetakesucroseasthesourceofcarbonprecursor.The influence of different preparation conditions, such as TEOS/sucrose,H2O/TEOS, pH, gel temperature, Carbonization temperature, and so on, onthe pore structure of carbon mixing the different source of carbon precursorand tetraethoxy silane(TEOS) as silica template to make controlled porestructure of carbon (ZCT carbon)TEOS : H2O:EtOH=1:4.39:6.88 as thebenchmark was studied. By the aid of nitrogen adsorption measurement atlow temperature, samples when the quantity of TEOS is15ml, sucrose is 3g,H2O is 7.5ml,HCl is 3.0ml, gel temperature is 80℃adding andcarbonization temperature is 850℃relatively effiective results. Underoptimum synthesis conditions a mesoporous carbon with a high surface areaand a narrow pore size distribution taking silica-sol as silica precursor wasproduced.Thethree-dimensionallyinterconnectedsilicastructureseffectivelyfunctionedasthetemplatefortheporouscarbonmaterials.Under optimum synthesis conditions the influence of adding surfactant,organic agent, drying control chemical additives on the pore structure ofcarbon, where tetraethoxy silane(TEOS) was used as the source of silicatemplateandsucroseasthecarbonprecursor,wasstudied.Adsorption of formaldehyde and methylene blue solution of dynamicadsorption experiments is taken by those mesoporous carbon with a highsurface area and a narrow pore size distribution selected from thoseexperimentsabove.