Synthesis of vanadium and chromium carbides (V8C7–Cr3C2) nanocomposite via an in situ precursor method
Synthesis of vanadium and chromium carbides (V8C7–Cr3C2) nanocomposite via an in situ precursor method
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DOI：
10.1007/s12598-015-0501-x
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发表时间：
2015-05
期刊：
影响因子：
8.8
通讯作者：
Zhiwei Zhao;Wenmeng Hu;Hongjuan Zheng;Feixiao Chen
中科院分区：
文献类型：
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作者：
Zhiwei Zhao;Wenmeng Hu;Hongjuan Zheng;Feixiao Chen
采用原位合成法制备了V8 C7-Cr 3C 2纳米复合材料。以钒酸铵、重铬酸钾和纳米炭黑为原料。采用X射线衍射（XRD）、扫描电子显微镜（SEM）、透射电子显微镜（TEM）、热重-差示扫描量热（TG-DSC）和X射线光电子能谱（XPS）等技术对产物进行了表征。结果表明，在1200 °C下反应1h，可合成平均晶粒尺寸为25.4nm的V8 C7-Cr 3C 2纳米复合材料。该方法所需的合成温度比制备钒和铬碳化物的常规方法所需的合成温度低至少200 °C。粉末显示出良好的分散性，并且主要由平均直径约为30 nm的球形或近球形颗粒组成。前驱体在整个反应过程中的失重率达到58wt%。反应过程中出现三个放热峰和四个吸热峰。试样表面主要由V、Cr、C和O元素组成。
In situ synthesis method was used to prepare V8C7–Cr3C2nanocomposite. Ammonium vanadate, ammonium dichromate and nanometer carbon black were used as raw materials. The products were characterized by X-ray diffractometry (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermogravimetric and differential scanning calorimetry (TG-DSC) and X-ray photoelectron spectroscopy (XPS) techniques. The results show that V8C7–Cr3C2nanocomposite with an average crystallite size of 25.4 nm can be synthesized at 1200 °C for 1 h. The synthesis temperature required by the method is at least 200 °C lower than that required by the conventional approaches for preparing vanadium and chromium carbides. The powders show good dispersion and are mainly composed of spherical or nearly spherical particles with a mean diameter of about 30 nm. The weight loss ratio of the precursor throughout the reaction process reaches 58 wt%. Three exothermic peaks and four endothermic peaks occur during the reaction. The surface of the specimen is mainly composed of V, Cr, C and O elements.