Chemical preparation and characterization of nitrogen-rich carbon nitride powders

Kawaguchi, Masayuki; Yagi, S.; Enomoto, Hikoe

doi:10.1016/j.carbon.2003.11.004

Cited by 69 publications

(50 citation statements)

References 31 publications

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“…Thus the two 15 N-signals for the NH and the NH 2 group must arise from a reduction of the 2D layer symmetry by the 3D arrangement. For a further assignment of the overlapping resonances of the CN 2 (NH x ) 13 C-signal we performed an iDCP experiment.…”

Section: Resultsmentioning

confidence: 99%

“…Samples were contained in 4 mm ZrO 2 rotors for the 15 13 C experiments was performed under broadband proton decoupling using a SPINAL-64 sequence with a nutation frequency of about 70 kHz. 48 The repetition times were set between 5 and 10 s. In the 2D experiments quadrature detection of the F 1 domain was achieved via TPPI and a SPINAL-64 decoupling (nutation frequency about 70 kHz) was applied during t 1 .…”

Section: Solid-state Nmr Spectroscopymentioning

confidence: 99%

“…2(b)). The spinning frequency was set to 5 kHz, the 1 H- 15 N CP contact time to 6 ms and the overall 15 N-13 C contact time to 10 ms. As shown in Fig. 2(b Fig.…”

Section: Solid-state Nmr Spectroscopymentioning

confidence: 99%

“…Although its existence has been postulated since 1834 the structure of individual melon layers could only recently be solved via electron diffraction and high-resolution 15 respectively. Furthermore, the homogeneity of the material under examination was investigated exploiting 15 N spin-diffusion.…”

mentioning

confidence: 99%

“…Furthermore, the homogeneity of the material under examination was investigated exploiting 15 N spin-diffusion. Based on force field methods 256 structure models with varying lateral arrangements between neighboring layers were created.…”

mentioning

confidence: 99%

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Tackling the stacking disorder of melon—structure elucidation in a semicrystalline material

Seyfarth

Lotsch

et al. 2010

Phys. Chem. Chem. Phys.

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In this work we tackle the stacking disorder of melon, a layered carbon imide amide polymer with the ideal composition (C 6 N 7 (NH)(NH 2 )). Although its existence has been postulated since 1834 the structure of individual melon layers could only recently be solved via electron diffraction and high-resolution 15 respectively. Furthermore, the homogeneity of the material under examination was investigated exploiting 15 N spin-diffusion. Based on force field methods 256 structure models with varying lateral arrangements between neighboring layers were created. For each model the M 2 were calculated allowing them to be ranked by comparing calculated and measured M 2 as well as via their force field energies. This allows the creation of markedly structured hypersurfaces with two distinctly favored shift vectors for the displacement of neighboring layers.

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Section: Resultsmentioning

confidence: 99%

Section: Solid-state Nmr Spectroscopymentioning

confidence: 99%

“…2(b)). The spinning frequency was set to 5 kHz, the 1 H- 15 N CP contact time to 6 ms and the overall 15 N-13 C contact time to 10 ms. As shown in Fig. 2(b Fig.…”

Section: Solid-state Nmr Spectroscopymentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

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Tackling the stacking disorder of melon—structure elucidation in a semicrystalline material

Seyfarth

Lotsch

et al. 2010

Phys. Chem. Chem. Phys.

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Two‐Dimensional Hexagonally‐Ordered Mesoporous Carbon Nitrides with Tunable Pore Diameter, Surface Area and Nitrogen Content

Vinu

2008

Adv Funct Materials

469

307

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Two‐dimensional mesoporous carbon nitride (MCN) with tunable pore diameters have been successfully prepared for the first time using SBA‐15 materials with different pore diameters as templates through a simple polymerization reaction between ethylenediamine (EDA) and carbon tetrachloride (CTC) by a nano hard‐templating approach. The obtained materials have been unambiguously characterized using X‐ray diffraction (XRD), N2 adsorption, high‐resolution transmission electron microscopy (HRTEM), electron energy loss spectroscopy (EELS), high‐resolution scanning electron microscopy (HRSEM), X‐ray photoelectron spectroscopy (XPS), Fourier transform infrared (FT‐IR) spectroscopy, and CHN analysis. The results show that the pore diameter of the MCN materials can be easily tuned from 4.2 to 6.4 nm without affecting their structural order. XRD, HRTEM and N2 adsorption results reveal that the materials are structurally well ordered with a two‐dimensional porous structure, a high surface area and a large pore volume. It is also demonstrated for the first time that the textural parameters such as the specific pore volume, the specific surface area and the pore diameter, and the nitrogen content of the MCN materials can be controlled by the simple adjustment of the EDA to CTC weight ratio. The carbon to nitrogen ratio of the MCN decreases from 4.3 to 3.3 with increasing EDA to CTC weight ratio from 0.3 to 0.9. The optimum EDA to CTC weight ratio required for fabricating the well‐ordered MCN materials with excellent textural parameters and high nitrogen content is around 0.45. The catalytic activity of the materials has been tested in the Friedel‐Crafts acylation of benzene using hexanoyl chloride as the acylating agent. The materials are highly active and show a high conversion and 100 % product selectivity to caprophenone.

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Preparation and Characterization of Well‐Ordered Hexagonal Mesoporous Carbon Nitride

et al. 2005

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Mesoporous carbon materials [1] with nanoscale pore sizes prepared from periodic inorganic silica templates [2±4] have been receiving much attention because of their versatility, as they are used in size-and shape-selective adsorption media, chromatographic separation systems, catalysts, nanoreactors, battery electrodes, capacitors, energy-storage devices, and biomedical devices. [1,5±8] Mesoporous carbon nitride (MCN) materials with two-dimensional (2D) pore systems promise access to an even wider range of applications because of their unique properties, such as semiconductivity, ability to intercalate, hardness, etc.[9]Until now, no such material has been reported. However, there are many reports on the synthesis and characterization of nonporous carbon nitride materials.[10±19] These materials can be prepared either from molecular or chemical precursors at very high temperatures. Very recently, Qiu and Gao have reported the chemical synthesis of non-porous turbostratic carbon nitride crystallites from polymerized ethylenediamine and carbon tetrachloride.[10] Here, we used a similar chemical method for the preparation of a highly ordered mesoporous carbon nitride material, designated MCN-1, which has a uniform pore size distribution, high specific surface area, and specific pore volume. The material has a highly ordered hexagonal array of a 2D pore system with a lattice constant of 9.52 nm, and the structural symmetry of the well-known parent 2D mesoporous silica template, SBA-15, is retained. The MCN-1 material has great potential for applications, e.g., in catalysis, gas storage, lubrication, biomolecule adsorption, and drug delivery. We believe that its existence opens other possible paths for the preparation of various mesoporous carbon nitrides with different dimensional structures using other inorganic mesoporous-silica templates and carbon and nitrogen precursors.In a typical synthesis, the calcined mesoporous silica SBA-15 [20] was added to a mixture of ethylenediamine and carbon tetrachloride. The resultant mixture was refluxed and stirred at 90 C for 6 h. The template carbon nitride polymer composites were then heat-treated in a nitrogen flow to carbonize the polymer. The mesoporous carbon nitride was recovered after dissolution of the silica framework in 5 wt.-% hydrofluoric acid. The final product was washed several times with ethanol and dried overnight at 100 C. The ordered mesoporous carbon nitride MCN-1 structure was investigated by powder X-ray diffraction (XRD) and nitrogen gas adsorption measurements. The X-ray diffraction pattern of the MCN-1 material showed three clear peaks, which can be assigned to the (100), (110), and (200) diffractions of a 2D hexagonal lattice (space group p6mm) with a lattice constant a 100 = 9.52 nm. The pattern is similar to the XRD pattern of the parent mesoporous silica template SBA-15, which consists of a hexagonal arrangement of cylindrical pores; these pores are interlinked by the micropores present in the walls (Fig. 1a). Such materials with one-dimensional...

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Chemical preparation and characterization of nitrogen-rich carbon nitride powders

Cited by 69 publications

References 31 publications

Tackling the stacking disorder of melon—structure elucidation in a semicrystalline material

Tackling the stacking disorder of melon—structure elucidation in a semicrystalline material

Two‐Dimensional Hexagonally‐Ordered Mesoporous Carbon Nitrides with Tunable Pore Diameter, Surface Area and Nitrogen Content

Preparation and Characterization of Well‐Ordered Hexagonal Mesoporous Carbon Nitride

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