纳米碲化铋化合物的溶剂热合成与热电性能

Hydrothermal Synthesis and Thermoelectric Properties of Nanostructured Bismuth Telluride

采用溶剂热法合成纳米结构碲化铋化合物,初始原料为氯化铋、亚碲酸钠、氢氧化钠、表面活性剂EDTA二钠,以及还原剂硼氢化钠。将初始原料的混合水溶液经过不同的预处理,在453 K热处理后得到黑色粉末产物,用水和乙醇多次洗涤、真空干燥后,得到形貌各异的纳米碲化铋化合物粉体。粉体的形貌与合成过程和表面活性剂有关,论文对三者的相互关系和影响机理进行了分析和探讨。所得纳米碲化铋粉体经SPS烧结制备成块体,其综合热电性能优于商用碲化铋块体材料,300 K时的ZT值为0.958。

The nanostructured bismuth telluride was synthesized using a hydrothermal method.The initial reagents were bismuth chloride,sodium tellurite,sodium hydroxide,surfactant of disodium ethylenediamine tetraacetic（EDTA-2Na）,and reductant of sodium borohydride.The mixed aqueous solution of reagents was preprocessed and heat-treated at 453 K,and then the black product could be obtained.The bismuth telluride powder with different shapes was obtained after the black products were washed by distilled water and absolute ethyl alcohol to eliminate the dissoluble irons and organic compounds,and finally dried in vacuum.The shape of powder has close relation to synthesis procedure and surfactant.The relationships between the shape and both influencing factors were discussed and analyzed in this paper.The bulk material was prepared by SPS sintering with nanostructured bismuth telluride.The ZT value of the bulk is 0.958 at 300 K,which is higher than that of bulk with commercial bismuth telluride.