Facile route to prepare TaC, NbC and WC nanoparticles

Abstract

By a novel solid-state reaction process using amorphous C 3 N 4 (a-C 3 N 4 ) and transition metal oxides as starting reagents, cubic TaC, NbC and hexagonal WC nanoparticles were successfully synthesized at 1150 ℃. The products were characterized by power X-ray diffraction (XRD), field-emission scanning electron microscope (FE-SEM), energy-dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM) and high-resolution TEM (HRTEM). The experimental results show that a-C 3 N 4 obtained by the reaction between C 3 N 3 Cl 3 and Li 3 N is a highly efficient carburation reagent and the transition metal oxides are completely transformed into the corresponding metal carbide nanoparticles at 1150 ℃, respectively, which is significantly lower than that reported for the traditional preparation of carbides, typically＞1600 ℃. The TaC, NbC and WC nanoparticles are found to have an average particle size of 10 nm, 15 nm and 8 nm by TEM observation, respectively.

Large scale synthesis and formation mechanism of highly magnetic and stable iron nitride (ε-Fe3N) nanoparticles

“…Nitrides of different transition metals have gained technological importance owing to their enhanced magnetic properties coupled with greater stability and corrosion resistance. 1,2 It is found that the physical and chemical properties of these materials are essentially dependent upon the nitrogen content in the system. 3 Iron nitrides, as a subject of research revealed that the nitrogen content is dependent on the diverse crystal structures and phases of iron nitrides, such as g-FeN (NaCl structure), x-Fe 2 N (orthorhombic structure), 3-Fe 3 N (hexagonal structure), g 0 -Fe 4 N and a 00 -Fe 16 N 2 (cubic structure).…”

Synthesis of WN(NMe2)3 as a Precursor for the Deposition of WNx Nanospheres

“…Darkening of the solid to red-brown was observed under vacuum, and sublimation of 1 (90-105°C at 10 -1 Torr) was accompanied by substantial decomposition (Ͼ 40 %). [61] Although WN x nanoparticles have been synthesized previously, [61][62][63][64] their synthesis at low temperature via pyrolysis has not been reported. Crystals suitable for X-ray structure determination were obtained by vapor diffusion of pentane into a concentrated diethyl ether solution of 1 at low temperature.…”

“…1 H and 13 C NMR spectra of 1 in [D 6 ]benzene indicated the chemical equivalence of all six methyl groups due to symmetry (C 3v ) and free rotation of the dimethylamide ligands. In previous studies, WN x nanoparticles were synthesized at high temperature by thermolysis, [61,62] pulsed laser-ablation, [63] and a "urea glass" technique. Compound 1 adopts a pseudo-tetrahedral geometry, as can be seen in the ORTEP representation ( Figure 2).…”

“…Although WN x nanoparticles have been synthesized previously,61–64 their synthesis at low temperature via pyrolysis has not been reported. In previous studies, WN x nanoparticles were synthesized at high temperature by thermolysis,61,62 pulsed laser‐ablation,63and a “urea glass” technique 64. Figure 3 shows a field emission SEM (FESEM) image of a WN x nanoparticle cluster obtained from delivering a 0.017 M solution of 1 in benzene at a substrate temperature of 75 °C.…”

Synthesis of niobium(iv) carbide nanoparticles via an alkali-molten-method at a spatially-limited surface of mesoporous carbon

“…Regarding this, the preparation of nano-sized NbC has been addressed by a lot of researchers to increase active sites per weight on the catalysis. 6,[21][22][23][24][25][26][27][28][29][30][31][32] Recently, Tour and Zhao et al synthesized NbC nanoparticles with ca. 20 nm of size via novel ash Joule heating in the reactor composed of capacitor banks, electrodes, quartz and a carbon source.…”