Synthesis And Characteristic Of Hierarchical Porous Carbon Materials

Hierarchical porous carbon materials with different pore structure have goodmacromolecules passing ability, developed pore structure and high surface area, and so on.So these carbon materials, which overcome the defects of single pore structure for themonomodal porous materials, have attracted much attention for catalyst supports,supercapacitor and separation.In this paper, using the templating method as the predominant orientation,hierarchical porous carbon materials can be synthesized by simple impregnation andencapsulating methods. And the effect of different parameters is observed by relativecharacteristics. The results are showed as follows:1) Using conventional ionic liquids (1-hexadecyl-3-methylimidazolium bromide) asprecursor, and monodisperse silica spheres (250nm) as template, mesoporous shell/hollowcore porous carbon materials has been synthesized. These carbon materials with nitrogendoping (3.2%) have uniform pore size and thin shell (5-12nm). all samples feature thepore size distributions with three centers at2.4,3.6and~13nm. In addition, ionic liquidswith different carbon chain and different particle size of monodisperse silica spheres arechosen as carbon sources and hard-templating to prepare mesoporous shell/hollow coreporous carbon materials according to the same procedures.2) A simple solid-solid grinding/templating route with the ILs of1-cyanoethyl-3-methylimidazolium chloride as precursor and SBA-15as template, isemployed for the synthesis of N-doped hierarchical porous carbon materials. And thegraphitization is promoted by the elevated carbonized temperature. Furthermore, we alsointroduce transition metal (e.g. ferric salt) into the walls of carbon materials by thesolid-solid grinding. The existence of α-Fe particles (5-8nm) in the magnetic hierarchicalporous carbon materials is observed. What’s more, some hollow tubular morphology,which is irregular in shape and size (neither straight nor uniform), are revealed. The ironparticles may play the catalytic role for the formation of tubular structure. The magnetichierarchical porous carbon materials behave excellent adsorption capacity for Cu2+ioncompared with the conventional mesoporous carbon CMK-3. The magnetic hierarchicalporous carbon materials in aqueous solution can be readily separated by an externalmagnetic field. So these carbon materials have potential in the applications of adsorptionof heavy metal cations for water treatments. 3) A facile aqueous route is employed to prepare macro-mesoporous or mesoporousshell/hollow core porous carbon materials via a dual-template method (usingmonodisperse silica spheres as solid template and F127as soft template). Changing theweight ratio of SiO2/F127, it can be realized that ruleless macro-mesoporous carbonmaterials is transformed into the core/shell carbon materials. Mesoporous shell/hollowcore porous carbon materials have uniform in size (260nm) and thin shell thickness of5nm. And the shell thickness on the carbon materials has the existence of numerousmesoporous centred at6-9nm. It is worth mentioning that3D ordered macro-mesoporouscarbon materials has also been fabricated. In addition, the different sizes of silica spheres(30nm,50nm and80nm) can also be chosen as solid templates to synthesize themesoporous shell/hollow core carbon materials according to the same procedures.