Han Guang, Chen Zhi-Gang, Yang Lei, Hong Min, Drennan John, Zou Jin
Materials Engineering and ‡Centre for Microscopy and Microanalysis, The University of Queensland , Brisbane QLD 4072, Australia.
ACS Appl Mater Interfaces. 2015 Jan 14;7(1):989-95. doi: 10.1021/am5078528. Epub 2014 Dec 24.
Bi2Te3 polycrystalline whiskers consisting of interconnected nanoplates have been synthesized through chemical transformation from In2Te3 polycrystalline whisker templates assembled by nanoparticles. The synthesized Bi2Te3 whiskers preserve the original one-dimensional morphology of the In2Te3, while the In2Te3 nanoparticles can be transformed into the Bi2Te3 thin nanoplates, accompanied by the formation of high-density interfaces between nanoplates. The hot-pressed nanostructures consolidated from Bi2Te3 polycrystalline whiskers at 400 °C demonstrate a promising figure of merit (ZT) of 0.71 at 400 K, which can be attributed to their low thermal conductivity and relatively high electrical conductivity. The small nanoparticles inherited from the polycrystalline whiskers and high-density nanoparticle interfaces in the hot-pressed nanostructures contribute to the significant reduction of thermal conductivity. This study provides a rational chemical transformation approach to design and synthesize polycrystalline microstructures for enhanced thermoelectric performances.
由相互连接的纳米片组成的Bi2Te3多晶须已通过由纳米颗粒组装而成的In2Te3多晶须模板的化学转化合成。合成的Bi2Te3晶须保留了In2Te3的原始一维形态，而In2Te3纳米颗粒可转化为Bi2Te3薄纳米片，同时在纳米片之间形成高密度界面。在400℃下由Bi2Te3多晶须固结而成的热压纳米结构在400K时显示出有前景的优值（ZT）为0.71，这可归因于其低热导率和相对高的电导率。热压纳米结构中从多晶须继承的小纳米颗粒和高密度纳米颗粒界面有助于显著降低热导率。本研究提供了一种合理的化学转化方法，用于设计和合成具有增强热电性能的多晶微结构。
