Tailoring the Mesoporous Texture of Graphitic Carbon Nitride

Recently, graphitic carbon nitride (g-C3N4) materials have received a great attention from many researchers due to their various roles as a visible light harvesting photocatalyst, metal-free catalyst, reactive template, nitrogen source of nitridation reaction, etc. g-C3N4 could be prepared by temperature-induced polymerization of cyanamide or melamine. In this study, we report a preparation of mesoporous graphitic carbon nitrides with tailored porous texture including pore size, and specific surface area from cyanamide and colloidal silica nanoparticles (Ludox). At first, cyanamide-silica nanocomposites were prepared by mixing colloidal silica with different size in the range of 7 similar to 22 nm and cyanamide, followed by evaporating the solvent in the resulting mixture. Mesoporous g-C3N4 samples were prepared by calcining cyanamide-silica nanocomposite at 550 degrees C for 4 hrs and removing the silica nanoparticles by using ammonium hydrogen fluoride. The formation of g-C3N4 was confirmed by the sharp (002) peak (d = 3.25 angstrom) of graphitic interlayer stacking, and the broad (100) peak (d = 6.86 angstrom) of in-plane repeating unit in the X-ray diffraction patterns. According to N-2 adsorption-desorption analysis, the pore size of mesoporous carbon nitrides was similar to the size of colloidal silica used as hard template (7 similar to 22 nm). The specific surface area of mesoporous g-C3N4 could be tailored in the range of 189 m(2)/g similar to 288 m(2)/g.