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Ordered mesoporous carbons (OMC), were synthesized by nanocasting using ordered mesoporous silica as hard templates. Ordered mesoporous carbons CMK-1 and CMK-3 were prepared from MCM-48 and SBA-15 materials with pore diameters of 3.4 nm and 4.2 nm, respectively. Mesoporous carbons can be effectively modified for CO2 adsorption with amine functional groups due to their high affinity for CO2. Polyaniline (PANI)/mesoporous carbon nanocomposites were synthesized from in-situ polymerization by dissolving OMC in aniline monomer. The polymerization of aniline molecules inside the mesochannels of mesoporous carbons has been performed by ammonium persulfate. The nanocomposition, morphology, and structure of the nanocomposite were investigated by nitrogen adsorption-desorption isotherms, Fourier Transform Infrared (FT–IR), X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and thermo gravimetric analysis (TGA). CO2 uptake capacity of the mesoporous carbon materials was obtained by a gravimetric adsorption apparatus for the pressure range from 1 to 5 bar and in the temperature range of 298 to 348 K. CMK-3/PANI exhibited higher CO2 capture capacity than CMK-1/PANI owing to its larger pore size that accommodates more amine groups inside the pore structure, and the mesoporosity also can facilitate dispersion of PANI molecules inside the pore channels. Moreover, the mechanism of CO2 adsorption involving amine groups is investigated. The results show that at elevated temperature, PANI/mesoporous carbon nanocomposites have a negligible CO2 adsorption capacity due to weak chemical interactions with the carbon nanocomposite surface. 相似文献
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A. Vinu P. Srinivasu M. Takahashi T. Mori V.V. Balasubramanian K. Ariga 《Microporous and mesoporous materials》2007,100(1-3):20-26
The mesoporous carbon materials prepared by inorganic templating technique using mesoporous silica, SBA-15 as a template and sucrose as a carbon source, have been systematically investigated as a function of sucrose to mesoporous silica composition, with a special focus on controlling the mesoporous structure, surface morphology and the textural parameters such as specific surface area, specific pore volume and pore size distribution. All the materials have been unambiguously characterized by XRD, N2 adsorption–desorption isotherms, high-resolution transmission electron microscopy, high-resolution field emission scanning electron microscopy, and Raman spectroscopy. It has been found that the porous structure, morphology and the textural parameters of the mesoporous carbons materials, CMK-3-x where x represent the sucrose to silica weight ratio, can be easily controlled by the simple adjustment of concentration of sucrose molecules. It has also been found that the specific surface area of the mesoporous carbon materials systematically increases with decreasing the sucrose to silica weight ratio. Moreover, the specific pore volume of the materials increases from 0.57 to 1.31 cm3/g with decreasing the sucrose to silica weight ratio from 5 to 1.25 and then decreases to 1.23 cm3/g for CMK-3-0.8. HRTEM and HR-FESEM also show a highly ordered pore structure and better surface morphology for CMK-3-1.25 as compared to other materials prepared in this study. Thus, it can be concluded that the sucrose to silica weight ratio of 1.25 is the best condition to prepare well ordered mesoporous carbon materials with good textural parameters, pore structure and narrow pore size distribution. 相似文献
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Direct fabrication of mesoporous carbons using in-situ polymerized silica gel networks as a template
Sangjin Han 《Carbon》2003,41(8):1525-1532
Mesoporous carbons were synthesized by in-situ polymerized silica gel networks as a template. The co-condensation of carbon precursor (sucrose) and silica precursor (sodium silicate) followed by heat treatment generated a carbon/silica nanocomposite. After etching the silica template, mesoporous carbons were obtained. Under optimum synthesis conditions a mesoporous carbon with a high surface area of >800 m2/g and a narrow pore size distribution centered at 3 nm was produced. The three-dimensionally interconnected silica structures effectively functioned as the template for the porous carbon materials. 相似文献
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An investigation of fractal characteristics of mesoporous carbon electrodes with various pore structures 总被引:2,自引:0,他引:2
Fractal characteristics of mesoporous carbon electrodes were investigated with various pore structures using the N2 gas adsorption method and the transmission electron microscopy (TEM) image analysis method. The mesoporous carbons with various pore structures were prepared by imprinting mesophase pitch used as a carbonaceous precursor with different colloidal silica particles. All imprinted mesoporous carbons were composed of two groups of pores produced from the carbonisation of mesophase pitch and from the silica imprinting. The overall surface fractal dimensions of the carbon specimens were determined from the analyses of the N2 gas adsorption isotherms. In order to distinguish the surface fractal dimension of the carbonisation-induced pore surface from that fractal dimension of the silica-imprinted pore surface, the individual surface fractal dimensions were determined from the image analyses of the TEM images. From the comparison of the overall surface fractal dimension with the individual surface fractal dimensions, it was recognised that the overall surface fractal dimension is crucially influenced by the individual surface fractal dimension of the silica-imprinted pore surface. Moreover, from the fact that the silica-imprinted pore surface with broad relative pore size distribution (PSD) gave lower value of the individual surface fractal dimension than that pore surface with narrow relative PSD, it is concluded that as the silica-imprinted pores comprising the carbon specimen agglomerate, the individual surface fractal dimension of that pore surface decreases. 相似文献
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Mesoporous carbons prepared by an inverse replica technique have been used as electrodes for electrochemical capacitors. Such well-sized carbons were prepared from mesostructured SBA-16 silica materials that served as templates whereas polyfurfuryl alcohol was the carbon precursor. Two highly mesoporous carbons characterized by 3 and 8 nm average pore diameter were tested in various electrolytic solutions (acidic, alkaline and aprotic).It can be concluded that templated mesoporous carbons with tailored pore size distribution are very promising materials to be used as electrodes in supercapacitors. The design of their pore size allows suiting the dimensions of electrolyte ions and efficient charging of the electrical double layer is achieved especially at high current load. Definitively better capacitance performance has been found for carbon with 3 nm pores range, however, cycling performance depends not only on the pore size. 相似文献
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In this paper the fabrication and characterization of graphitizable and graphitized porous carbons with a well-developed mesoporosity is described. The synthetic route used to prepare the graphitizable carbons was: (a) the infiltration of the porosity of mesoporous silica with a solution containing the carbon precursor (i.e. poly-vinyl chloride, PVC), (b) the carbonisation of the silica–PVC composite and (c) the removal of the silica skeletal. Carbons obtained in this way have a certain graphitic order and a good electrical conductivity (0.3 S cm−1), which is two orders larger than that of a non-graphitizable carbon. In addition, these materials have a high BET surface area (>900 m2 g−1), a large pore volume (>1 cm3 g−1) and a bimodal porosity made up of mesopores. The pore structure of these carbons can be tailored as a function of the type of silica selected as template. Thus, whereas a graphitizable carbon with a well-ordered porosity is obtained from SBA-15 silica, a carbon with a wormhole pore structure results when MSU-1 silica is used as template. The heat treatment of a graphitizable carbon at a high temperature (2300 °C) allows it to be converted into a graphitized porous carbon with a relatively high BET surface area (260 m2 g−1) and a porosity made up of mesopores in the 2–15 nm range. 相似文献
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Weijie Dai Mingbo Zheng Yu Zhao Shutian Liao Guangbin Ji Jieming Cao 《Nanoscale research letters》2010,5(1):103-107
Three-dimensional cubic ordered mesoporous carbons with tunable pore sizes have been synthesized by using cubic Ia3d mesoporous KIT-6 silica as the hard template and boric acid as the pore expanding agent. The prepared ordered mesoporous
carbons were characterized by powder X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and
nitrogen adsorption–desorption analysis. The results show that the pore sizes of the prepared ordered mesoporous carbons with
three-dimensional cubic structure can be regulated in the range of 3.9–9.4 nm. A simplified model was proposed to analyze
the tailored pore sizes of the prepared ordered mesoporous carbons on the basis of the structural parameters of the silica
template. 相似文献
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Easy synthesis of an ordered mesoporous carbon with a hexagonally packed tubular structure 总被引:1,自引:0,他引:1
Ordered mesoporous carbon with hexagonal arrays of tubes (CMK-5) was successfully synthesized via a nanocasting process by directly using SBA-15, instead of AlSBA-15, as a template, furfuryl alcohol as a carbon source and oxalic acid as the catalyst. The time consuming impregnation of SBA-15 with aluminum could be saved. The as-synthesized CMK-5 exhibits a tubular structure with double pore system. The loading amount of carbon precursor on the pore walls of SBA-15 is the key factor for the formation of the CMK-5 structure with two-dimensional hexagonal arrays of tubes, and the pore diameter can be adjusted by varying the loading amount of the carbon precursor. The CMK-5 carbon exhibits high apparent surface area up to ∼2500 m2/g and high pore volume reaching ∼2 cm3/g, which is due to the unique structure of CMK-5. The characterization results confirmed that carbonization under argon atmosphere instead of vacuum is sufficient for the structural formation of CMK-5 carbons, and can be used as an alternative pathway to prepare tubular-type carbons. 相似文献
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Despoina D. Asouhidou Kostas S. Triantafyllidis Nikolaos K. Lazaridis Kostas A. Matis Seong-Su Kim Thomas J. Pinnavaia 《Microporous and mesoporous materials》2009,117(1-2):257-267
In the present study two synthetic mesoporous carbons, a highly ordered CMK-3 sample with hexagonal structure and a disordered mesoporous carbon (denoted DMC) were investigated for the sorption of Remazol Red 3BS (C.I. 239) dye in comparison to three commercial activated carbons and a HMS mesoporous silica with a wormhole pore structure. The structural, porosity and surface characteristics of the materials were evaluated using XRD, TEM, N2 porosimetry, FT-IR spectroscopy and zeta-potential measurements. Optimal dye sorption occurred at pH ~2. Equilibrium sorption data followed the Langmuir model and showed that the two synthetic mesoporous carbons exhibit higher sorption capacities (qmax ~ 500–580 mg/g at 25 °C) in comparison to the commercial activated carbons which possessed either microporous (Takeda 5A and Calgon carbon) or combined micro-/mesoporous (Norit SAE-2) structures and to the HMS mesoporous silica. Thermodynamic parameters as the change in free energy, enthalpy, and entropy of sorption were also estimated. Kinetic studies were carried out and showed a rapid sorption of dye in the first ca. 30 min while equilibrium was reached after ca. 3 h. The sorption kinetics of dye was best described by a second-order kinetic model. A surfactant enhanced carbon regeneration (SECR) technique was used to regenerate the dye-loaded carbon sorbents. 相似文献
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《Carbon》2013
Nitrogen-doped mesoporous carbons (NMCs) with ordered to disordered pore structures were fabricated on SBA-15 modified with different concentrations of tetraethyl orthosilicate using pyrrole as a carbon source. The carbonization temperature of NMCs was maintained at 800 °C so that the amount and type of nitrogen functionalities were constant. Pt nanoparticles (NPs) were deposited onto NMCs using a modified polyol process. N2 adsorption isotherms, transmission electron microscopy, X-ray diffraction, Raman spectroscopy, and X-ray photoelectron spectroscopy were used to characterize NMCs and Pt NPs. A significant shift in binding energy was found in Pt NPs deposited on NMC with disordered pore structure compared to Pt NPs deposited on NMC with ordered pore structure. Pt NPs deposited on NMC with the disordered pore structure had the highest intrinsic oxygen reduction reaction (ORR) activity among the Pt/NMC catalysts. It showed that the interaction between Pt NPs and NMCs could be modulated for enhancement of the ORR activity of Pt NPs by changing the pore structure of NMCs. 相似文献
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Ajayan Vinu Masahiko Miyahara Toshiyuki Mori Katsuhiko Ariga 《Journal of Porous Materials》2006,13(3):379-383
Novel large pore cage type mesoporous carbons, carbon nanocages, abbreviated as CKT (carbon from KIT-5) using three dimensional
large cage type face centered cubic Fm3m mesoporous silica materials (KIT-5) as inorganic templates prepared at different temperature were synthesized and characterized.
The specific pore volume and the specific surface area of the carbon nanocage materials are much higher as compared to CMK-3
mesoporous carbon. Adsorption of amino acid (histidine), flavonoid (catechin), vitamin (vitamin E, α-tocopherol), endocrine
disrupter (nonylphenol), and enzyme (lysozyme) over the carbon nanocage materials was also studied. Interestingly, carbon
nanocage materials showed an unusual adsorption capacity of catechin in aqueous solution. The CKT carbon nanocage materials
also exhibited higher adsorption capabilities of other biomolecules used in this study as compared with the CMK-3 mesoporous
carbon. 相似文献
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Ajayan Vinu Masahiko Miyahara Toshiyuki Mori Katsuhiko Ariga 《Journal of Porous Materials》2006,13(3-4):379-383
Novel large pore cage type mesoporous carbons, carbon nanocages, abbreviated as CKT (carbon from KIT-5) using three dimensional large cage type face centered cubic Fm3m mesoporous silica materials (KIT-5) as inorganic templates prepared at different temperature were synthesized and characterized. The specific pore volume and the specific surface area of the carbon nanocage materials are much higher as compared to CMK-3 mesoporous carbon. Adsorption of amino acid (histidine), flavonoid (catechin), vitamin (vitamin E, α-tocopherol), endocrine disrupter (nonylphenol), and enzyme (lysozyme) over the carbon nanocage materials was also studied. Interestingly, carbon nanocage materials showed an unusual adsorption capacity of catechin in aqueous solution. The CKT carbon nanocage materials also exhibited higher adsorption capabilities of other biomolecules used in this study as compared with the CMK-3 mesoporous carbon. 相似文献
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《Microporous and mesoporous materials》2007,98(1-3):189-199
Mesoporous silica materials have been synthesized through sol–gel reaction using inexpensive sodium silicate as source of silica and low cost hydroxy carboxylic acid compounds as templates/pore forming agents. The material measured surface area of 1014 m2/g, pore diameter of 65 Å and pore volume of 1.4 cc/g when parameters like time and temperature of synthesis along with mole ratio of TA/SiO2 were optimized. Here TA stands for tartaric acid. Carbonization of sucrose inside the pores of above silica material at 900 °C followed by removal of silica framework using aqueous ethanoic solution of NaOH gave rise to mesoporous carbon material. The resulting materials were characterized by N2-sorption, FTIR spectroscopy, X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy, thermal analysis and cyclic voltammetry. Three dimensional interconnecting wormhole channel arrangement of mesoporous silica template leads to mesoporous carbon replica with surface area of 1200 m2/g. X-ray photoelectron spectroscopic study (XPS) of the mesoporous carbon material shows the concentration of carbon atom in the range of 97–98% with 1–2% oxygen and negligible amount of silica. The electrochemical double layer capacitance behavior of carbon material with the specific capacitance value of 88.0 F/g at the scan rate of 1 mV/s appears to be promising. 相似文献
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目前制备有序介孔碳的方法工艺复杂、繁琐耗时,为了简化其制备工艺,缩短实验流程,本文提出一种不需要添加额外溶剂直接制备有序介孔碳的方法。以三嵌段共聚物F127为模板剂,自制低分子量酚醛树脂为碳前体,制备了具有二维六方结构的介孔碳。采用红外光谱对酚醛树脂和F127进行表征,研究了两者之间的作用力;采用X射线衍射、透射电镜和N2吸附/脱附等手段对介孔碳结构进行表征,研究了酚醛树脂的合成温度和模板剂用量对介孔碳结构的影响。结果表明酚醛树脂合成温度为70℃,F127:PF=1时,得到的介孔碳比表面积、孔容和孔径分别为490m2/g、0.41cm3/g和4.15nm。 相似文献
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Quenched solid density functional theory (QSDFT) model for characterization of mesoporous carbons using nitrogen adsorption is extended to cylindrical and spherical pore geometries. The kernels of theoretical isotherms in the range from 0.4 to 50 nm are constructed accounting for different possible variations of the pore shapes in micropore and mesopore regions. The results of QSDFT method are illustrated with experimental data on adsorption on novel CMK-3 and 3DOm carbons. The proposed method is recommended for pore size distribution calculations for micro–mesoporous carbons obtained through various templating mechanisms. 相似文献
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介孔碳是一类新型的具有巨大比表面积和孔体积的介孔材料,可以通过不同的方法合成并对其孔结构和形貌进行调节。本文主要综述了介孔碳及介孔碳基复合材料的合成方法,对比阐述了不同方法制备的介孔碳材料所具备的孔道结构和形貌。介绍了将不同非金属和金属元素及其氧化物掺杂在介孔碳中合成复合材料,发现制备的复合材料具有更优的性能且掺杂元素不同复合材料的形貌和孔道结构不同。此外,简要说明了介孔碳及碳基复合材料在环境、催化、储能、电化学和生物医学等方面的应用,指出其在各个领域的应用仍存在不足。调整介孔碳的孔结构和表面性能、采用更简便易控制的合成方法将成为制备介孔碳及碳基材料的主要研究方向。 相似文献