Ionothermal Synthesis of Crystalline, Condensed, Graphitic Carbon Nitride

Herein we report the synthesis of a crystalline graphitic carbon nitride, or g-C3N4, obtained from the temperature-induced condensation of dicyandiamide (NH2C(=NH)NHCN) by using a salt melt of lithium chloride and potassium chloride as the solvent. The proposed crystal structure of this g-C3N4 species is based on sheets of hexagonally arranged s-heptazine (C6N7) units that are held together by covalent bonds between C and N atoms which are stacked in a graphitic, staggered fashion, as corroborated by powder X-ray diffractometry and high-resolution transmission electron microscopy.