Preparation and Characterization of Well‐Ordered Hexagonal Mesoporous Carbon Nitride

Abstract

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...

Mesoporous carbon nitride–silica composites by a combined sol–gel/thermal condensation approach and their application as photocatalysts

“…11,12 Silica nanoparticles or mesoporous silicas can be used as hard templates to create porous carbon nitrides with ordered or disordered pore structures. 6,9,10,[13][14][15][16][17] Mesoporous carbon nitrides with high surface area and spherical pores of 12 nm arranged in non-regular fashion were for example prepared using silica nanoparticles as templates. 6 Ordered mesoporous carbon nitride with 2D hexagonal pore structure with relatively large mesochannels (10.7 nm) has been a Institut f€ ur Chemie, Sekr.…”

Adsorption studies of Pb(II) and Cu(II) ions on mesoporous carbon nitride functionalized with melamine-based dendrimer amine

“…These materials can be synthesized from either chemical or molecular precursors at high temperature. Qiu and Gao (Vinu et al 2005) have reported the chemical synthesis of non-porous turbostratic carbon nitride materials from polymerized ethylenediamine and carbon tetrachloride. Vinu et al have reported the synthesis of MCN-1 using SBA-15 as a template (Vinu et al 2007a, b).…”

The Effect of Mesoporous Carbon Nitride Modification by Titanium Oxide Nanoparticles on Photocatalytic Degradation of 1,3-Dinitrobenzene

“…The observation data from the original samples of all nanostructured carbons are in good agreement with that previously reported. 15 The wide-angle XRD patterns of titanium oxide modified mesoporous photocatalyst (Ti-MCN) in Fig. 3 as revealed by the peaks at 25.3°, 37.7°, 48.0° (Fig.…”

“…13 To have an improved photocatalytic efficiency, composite photocatalysts were designed by loading TiO 2 on certain support substrates with large surface areas. 14 Recently, Vinu et al 15 reported the synthesis of mesoporous CN materials based on pyridine-and benzene-ring building blocks by using mesoporous silica as a hard template and ethylenediamine (EDA) and carbon tetrachloride (CTC) as precursors.…”