Synthesis and Characterization of Nanostructured Niobium and Molybdenum Nitrides by a Two-Step Transition Metal Halide Approach

Nanosized NbNx (1.64 > x > 1.33) and MoNx (1.32 > x > 0.77) crystallites were synthesized at a relatively low temperature (>= 600 degrees C) through ammonolysis and nitridation of the corresponding metal chlorides. The ammonolysis reaction in anhydrous chloroform at room temperature and the nitridation mechanism during subsequent heat treatment was investigated using Fourier transform infrared spectroscopy, X-ray diffraction (XRD), thermogravimetric (TG), and mass spectroscopy analysis. The effects of the synthesis parameters on the stoichiometry, structure, specific surface area, density, and electronic conductivity of the final nitrides were studied using TGA, XRD, N-2 adsorption, high-resolution transmission microscopy, helium pycnometry, and four-point probe technique. Preliminary electrochemical responses of the obtained nitrides were studied using cyclic voltammetry to explore their possible use as electrochemical capacitors.