Template-Free One-Pot Synthesis of Porous Binary and Ternary Metal Nitride@N-Doped Carbon Composites from Ionic Liquids

Herein we present a straightforward synthesis approach toward composites of titanium, vanadium, and titanium vanadium nitride nanoparticles embedded in nitrogen-doped carbon. These materials can be easily prepared via the heat treatment of mixtures of the corresponding metal precursors TiCl4 or VOCl3 dissolved in the ionic liquid 1-butyl-3-methyl-pyridinium dicyanamide (Bmp-dca) as the nitrogen/carbon source. WAXS diffractograms and TEM pictures of the resulting materials reveal the presence of highly crystalline metal nitride nanoparticles with an average diameter of nm embedded in a graphitic carbon matrix. XPS measurements show that the carbon network is heavily doped with nitrogen; that is, it can be described as a nitrogen-doped carbon. Nitrogen sorption measurements show type I isotherms indicative of mainly microporous composites. The specific BET surface area increases with increasing amount of the metal precursor, and it is also dependent on the respective metal ion used. Under similar synthetic conditions, the specific surface areas for VN composites are higher than those of TiN materials, reaching values up to 550 m(2) g(-1) for VN. It is worth mentioning that these high surface areas can be reached without a template or etching; thus, it is an inherent structural feature of the composite. Furthermore, the use of ionic liquids as precursors offers the possibility for facile processing before material generation; that is, shaping, printing, or casting can be easily performed.