肼溶胶-凝胶法制备高比表面积纳米氮化钛粉体的研究

Synthesis of TiN Nanocrystals with High Specific Surface Area by Hydrazide Sol-gel Method

以无水肼作氮源,采用肼溶胶-凝胶技术(HSG)成功地制备了TiN粉体,研究了不同钛源、处理气氛及焙烧温度对TiN粉体晶化过程的影响,并对其形成机理进行了讨论.与氨气氮化法相比,该方法所需温度低、TiN的粒径小、比表面积大,并且分散均匀.

Nanocrystalline TiN with a high specific surface area was successfully prepared by the hydrazide sol-gel method with N2 H4 as the nitrogen source. The effects of Ti sources, heat-treatment atmospheres, and temperature on the crystallization of TiN powder were studied and the crystallization mechanism of TiN nanocrystals was also discussed. TiCI3 is superior to TiCI4 and isopropoxide in the formation of well-crystallized TiN nanocrystals. NH3 has the advantage over N2 and Ar in the complete removal of residual carbon in TiN powder. In comparison with the traditional temperature-programmed reduction under flowing NH3 atmosphere, the hydrazide sol-gel route requires a relatively low temperature on the one hand （600 ℃ ） and TiN powder prepared by this synthetic approach exhibits a small particle size（ 10 nm） and an exceedingly high specific surface area（ 〉 135 m^2/g） and disperses uniformly on the other hand. We expect that this methodology will provide a novel low-temperature route to synthesize nanocrystalline transition metal nitrides through choosing hydrazine as N-source precursor.