以Bi(NO3)3和Te粉为原料,水合肼为还原剂,采用水热法保温24h,分别在150℃和180℃制备了Bi2Te3纳米粉末。通过X射线衍射、透射电镜、扫描电镜等分析方法对产物的物相组成和微观形貌进行了表征。实验结果表明,水热法可以制备出纯相纳米级别的Bi2Te3粉末,并且晶粒尺寸随着反应温度升高有增大的趋势。最后采用高温高压法对纳米Bi2Te3粉末进行烧结,分析了烧结温度和压力对样品室温热电性能的影响。结果显示,在0.94GPa、753K条件下烧结后样品的室温功率因子达到16μW/(cm·K2)。
Bi2Tea nanopowders were synthesized by the hydrothermal method at 150℃ and 180℃for 24h using Bi(NOa)a and Te powder as the precursors,N2 H3 as reductant. X-ray diffraction (XRD), transmission electron mi- croscope (TEM), scanning electron microscope (SEM) were applied to analyze the phase distributions, microstruc- tures and grain sizes of the nanostructured BizTea. The results show that the pure orthorhombic nanowires are formed by the hydrothermal synthesis method, and the particle size increases with the reaction temperature increases. Bi2 Tea powders were sintered by high pressure and high temperature (HPHT) finally. The effects of pressure and tempera- ture on thermoelectric properties were investigated in room temperature. The result shows that the room temperature of power factor reaches 16/,W/(cm · K^2) for Bi2Tea synthesized at 0.94GPa and 753K.