A simple synthesis of mesoporous carbons with tunable mesopores using a colloidal template-mediated vapor deposition polymerization

Abstract

Mesoporous carbons with highly uniform and tunable mesopores were fabricated by one-step vapor deposition polymerization (VDP) using colloidal silica particles as templates and polyacrylonitrile (PAN) as a carbon precursor.Mesoporous carbons are used as catalysts, adsorbents and various supports. In particular, mesoporous carbons with narrow pore size distributions and tunable pore sizes are important in the field of size-selective separation, and can be applied as packing materials in chromatography or size-selective adsorbents. Recently, templating approaches have been extensively studied for the synthesis of mesoporous carbons using mesoporous and colloidal silicas as templates. Mesoporous silicas are representative porous silica templates. 1 Ryoo et al. reported the synthesis of ordered mesoporous carbons (CMKs) with high surface areas and large pore volumes from ordered mesoporous silica templates. 2 Compared to porous silica templating, the use of commercially available colloidal silicas as templates provides a more convenient way to fabricate mesoporous solids including carbons. 3 It does not require the pre-synthesis of suitable porous silica templates at a high cost and by a complicated synthetic procedure. Moreover, the pore diameter of the mesoporous carbon can be easily controlled using an appropriate colloidal silica, which is available in a wide range of particle sizes. Mallouk and co-workers synthesized mesoporous polymers with tunable pore sizes from colloidal silica templates. 4 Jaroniec and co-workers reported the synthesis of mesoporous carbons by a colloidal imprinting approach. 5 In colloidal silica templating, however, it is likely that silica aggregates composed of a few particles rather than a single silica particle act as templates for the formation of mesopores. 6 This leads to undesirable broadening of the pore size distribution in the resulting mesoporous carbon. 7 To date, impregnation of colloidal silica templates with carbon precursors has commonly depended on the wet chemical method, where the carbon precursor in the liquid state is inserted into the templates. Recently, our group reported that the vapor deposition polymerization (VDP) technique allows a simple route for the synthesis of inorganic-polymer and inorganic-carbon core-shell nanostructures by consecutive polymerization of vaporized monomer under vacuum onto the desired surface. 8 So far, VDP has been mainly performed to fabricate various thin films and core-shell nanostructures, 9 whereas considerably less attention has been paid to the application of VDP in colloidal templating. The VDP process makes it possible for monomer vapor to be polymerized even inside very small void spaces between colloidal particles without disrupting the characteristic of the colloidal template structure. In addition, it provides experimental simplicity such as a solvent-free system and no recovery process. In this communication, we report a simple route for the synthesis of mesoporous carbons with highly uniform and tunable mesopores using...

Heavy metal ion adsorption onto polypyrrole-impregnated porous carbon

“…Furthermore, a porous structure with interconnected pore was retained after the introduction of the PPy layer. This retained pore system is considered to be favorable for mass diffusion of guest molecules [13].…”

“…The detailed method and procedure for the preparation of porous carbon and its modification were reported by our previous publications [13,22]. In the functionalization of porous carbon, pyrrole monomers were introduced into a reactor containing a variable amount of porous carbon at room temperature under reduced pressure, and then vaporized by heating at 90 • C [23].…”

“…Porous carbons have been synthesized for various applications such as adsorption, catalyst support, and energy storage [13][14][15]. In particular, the functionalization of carbon materials could provide chemical affinity for specific guest molecules and improved dispersion in aqueous solution [16][17][18][19].…”

Recent Progress in the Synthesis of Porous Carbon Materials

“…Jang and his co-workers also reported the synthesis of mesoporous carbons via vapor deposition polymerization of polyacrylonitrile on the surface of silica particles. [39] Lu et al reported an aerogel-based approach to synthesize spherical mesoporous carbon particles. [40] In the synthesis, an aqueous solution containing sucrose and various silica templates was passed through an atomizer and dispersed into aerogel droplets.…”

Adsorption of lysozyme on spherical mesoporous carbons (SMCs) replicated from colloidal silica arrays by chemical vapor deposition

“…Previously, it has been demonstrated that the size of these windows could be facilely adjusted by varying the degree of contact among silica spheres through careful control of the sintering temperature [38]. Since the capillary evaporation in the desorption branch of the N 2 isotherm is associated with the structural 'win- dows' among the primary mesopores [37,39], one should be able to evaluate the size of the 'windows' by the PSD derived from the desorption branch, as shown in Fig. 4b.…”