ZnO基核壳结构纳米热电材料的制备与性能研究

With interesting nanoscale effect of physical and chemical properties and the structural tunability, core-shell nanostructured composites have recently attracted attention in thermoelectric community. Nevertheless, it is yet a great challenge to synthesize high-density bulk materials that retain the original core-shell nanostructure. In addition, there is a lack of study on the thermal stability and transport physics of these core-shell nanostructured bulk materials. In the present project, we propose to design and synthesize the ZnO based core-shell nanocomposites by tuning the chemical composition, size, morphology and interface, through which the thermoelectric properties can be significantly improved. The thermal stability of the core-shell nanostructure and the effect of the nanoscale interfaces on the thermoelectric transport properties will be investigated with the aid of the advanced material characterization techniques. With the experimental results, the correlation between the thermoelectric properties of the core-shell nanostructured composite and the nanoscale core-shell unit can be established, which provides useful reference for the design and development of novel high-temperature composite thermoelectric.

核壳结构纳米复合材料由于其纳米尺度特殊的物理、化学性质及结构可调控性，在热电材料领域开始得到关注。然而，获得高致密度、并保持原有纳米核壳结构的块体材料是目前面临的重要挑战。此外，纳米核壳结构的热稳定性及其热电输运机制仍有待深入和系统的研究。本项目拟选择ZnO基核壳结构纳米热电材料作为研究对象，通过核、壳材料的化学组成、尺寸、形貌及核壳界面的设计与调控，进而优化材料整体的热电输运性能。结合先进材料结构表征技术，深入探索并揭示核壳结构组织的热稳定性及其纳米尺度界面对热电输运性能的影响。依据实验结果，阐明核壳结构纳米复合材料热电性能与核壳结构单元的关联性，为探索和设计新型高温热电复合材料提供新的思路和参考。

核壳结构纳米复合材料由于其纳米尺度特殊的物理、化学性质及结构可调控性，在热电材料领域开始得到关注。本项目选择氧化物核壳结构纳米热电材料作为研究对象，通过核、壳材料的化学组成、尺寸、形貌及核壳界面的设计与调控，进而优化材料整体的热电输运性能。研究结果表明，通过水热溶剂热法、溶胶-凝胶法和放电等离子烧结技术可制备核壳结构块体纳米复合热电材料。相对于纯相材料，核壳结构复合材料的电学性能改善不明显，热导率降低，总体上ZT值没有得到提高，可通过进一步调控化学成分和微结构提高复合材料的热电性能。