Templated carbons carbonization method

Chen, X. Y., Y. Y. He, H. Song, and Z. J. Zhang. 2014. Structure and electrochemical performance of highly nanoporous carbons from benzoate-metal complexes by a template carbonization method for supercapacitor application. Carbon 72 410-420. 

Chen, X. Y., C. Chen, Z. J. Zhang, and D. H. Xie. 2013. Gelatin-derived nitrogen-doped porous carbon via a dual-template carbonization method for high performance supercapacitors. Journal of Materials Chemistry A 1 10903-10911. 

T. Kyotani, L. Tsai, A. Tomita, 1997. Formation of nanorods and nanoparticles in uniform carbon nanotubes prepared by a template carbonization method. Chemical Communications, 7 701-702. 

Chemically modified nanoporous carbons obtained using template carbonization method... 

In summary, we have presented a simple approach to synthesize hollow SiC spheres. The size of the hollow spheres depending on the size of the template carbon spheres. The shell of the spheres consists of a lot of twisted SiC nanowires with length of 5 20 pm and diameter of 50-500 nm, which is formed through a gas phase reaction. This technique presents a convenient method to synthesize hollow SiC spheres and an effective way to utilize fly ash. 

The other method for preparing ordered mesoporous materials is the so-called hard template method using hard mesoporous silica or replicated carbon templates. The metal precursors are filled into hard templates. In this method, heat treatment can be performed at a higher temperature without structural collapse and highly crystallised materials can be obtainedl ° ] (Figure 3.6). 

Historically, the hard template carbonisation method was first reported by Knox et al. in 1986. They demonstrated the synthesis of graphitised porous carbons for liquid chromatography separation by impregnation of spherical porous silica gel with phenolic resin and subsequent carbonisation and removal of silica gel. Since the first reported use of template carbonisation, the method has been employed extensively to prepare ordered porous carbons. A variety of inorganic porous templates including zeo-... 

In order to improve the structural ordering of zeolite-templated carbons, Ma et al. have investigated systematically the synthesis of microporous carbons using zeolite Y as hard template. They used a two-step method to prepare an ordered, microporous carbon with high surface area, which retained the structural regularity of zeolite Y by filling as much carbon precursor as possible into the zeolite pores so as to prevent any subsequent partial collapse of the resulting carbon framework. In the... 

Kim et al. [64] analyzed porous carbon by using colloidal sUica particles as templates. Carbon with micro, meso and macropores were obtained modifying the initial pH of the carbon precursor solutions. This fabrication method produces materials with narrow pore size distribution in a broad range of pore size. The fuel cell test showed better DMFC performance for carbons with high meso-macropore area with large pore than that with micropores. Again, this effect was attributed to the fact that meso and macropores produce a favorable dispersion of PtRu metal species and allow the access of perfluorosulfonate ionomer for the formation of the triple phase boundary. 

Unlike CMK-1 [62], here the ordered pore structure (see Figure 2.15b) is a true replica of SBA-15, without involving strnctural transformation that occurs when MCM-48 is nsed as a template [62,121], The overall porosity of CMK-3 is a combination of nniform pores in spaces between the ordered carbon nanorods and micropores within these nanorods. The carbon is mostly mesoporous, with a quite narrow PSD centered at about 4.5 nm, as calculated using the Barrett-Joyner-Halenda (BJH) method [120]. The carbon nanorods in CMK-3 are about 7 nm in diameter, and the centers of two adjacent rods are about 10 nm apart, whereas the surface-to-surface distance is about 3 nm, based on XRD and TEM results [120]. The carbon nanorods are interconnected by carbon spacers [122], as illustrated in Figure 2.14. Because the pore size of SBA-15 can be tuned simply by changing the synthesis conditions, the mesopore size of templated carbon can be tuned in the 3.0- to 5.2-nm range [123]. 

Preparing carbons with hierarchical pore structure is done by impregnation of preformed macropo-rous structures, such as silica colloids, with the carbon precursor gels, followed by precursor carbonization and macropore template dissolution. Although in hard-templated carbons, two particle sizes of the hard template are simultaneously required for the colloidal imprinting method the soft-templating method makes this procedure much simpler and broadens the selection of templates for the larger mesopores and macropores. 

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