کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1626034 | 1516443 | 2007 | 4 صفحه PDF | دانلود رایگان |
While there already exit some routes to prepare carbides, highly efficient and facile routes are still desired to meet the increasing demand on carbides. By a facile solid-state reaction process using graphite-like phase of C3N4 (g-C3N4) as the carbonizing reagent, we synthesized three technologically important carbides including cubic NbC and TaC, and hexagonal WC nanoparticles at relatively low temperature (1150 °C). 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 results show that g-C3N4 is a highly efficient carbonizing reagent and the oxides Nb2O5, Ta2O5 and WO3 are completely converted into the corresponding carbides at 1150 °C, which is significantly lower than that reported for the commercial preparation of the carbides, typically >1600 °C. The NbC, TaC and WC nanoparticles are found to have an average particle size of 4, 35 and 60 nm, respectively. An important feature of this solid-state reaction process is that g-C3N4 plays double roles as both efficiently reducing and carbonizing reagent.
Journal: Journal of Alloys and Compounds - Volume 430, Issues 1–2, 14 March 2007, Pages 237–240