N-型碲化铅纳米片的电化学制备及其热电性能研究

Abstract

PbTe是一类具有很高的热电转换效率的材料。本文以阴极化碲电极为碲源，3-巯基丙酸为保护剂，在水相中利用电化学方法制备了n-型PbTe纳米片。透射电子显微镜和X-射线衍射仪的结果表明合成产物是面心立方结构的PbTe纳米片，保护剂的存在会在加热过程中形成PbS，形成纳米尺寸的PbTe/PbS杂化材料；利用红外吸收光谱仪首次研究了合成PbTe的近红外吸收；用热电测量仪测定了PbTe纳米粒子的电阻率、Seebeck系数、热导率和品质因数ZT等热电性能参数，结果表明合成的PbTe纳米片的热导系数和品质因数得到较体相PbTe有明显的改善。该方法制备条件温和，操作简单，绿色环保。 PbTe is a kind of thermoelectric material of high thermoelectric conversion efficiency. In this papern-type PbTe nanoplates were prepared by using cathodic tellurium electrode as tellurium source and 3-mercaptopropionic acid as protective agent in the aqueous medium. The result of transmission electron microscopy and X-ray diffraction showed that as-prepared PbTe nanoplates were in face-centered cubic structure and PbS and nanoscale hybrid PbTe/PbS materials were formed during the heating process at presence of the protective agent. The near-infrared absorption of as-synthetic PbTe nanocrystals was firstly evaluated with infrared spectrophotometer. The thermoelectric performance including electrical resistivity, Seebeck coefficient, thermal conductivity and the figure of merit ZT was assessed with thermoelectric analyzer, which indicated that thermal conductivity and figure of merit of as-prepared PbTe nanocrystals were improved in contrast to the bulk materials. Furthermore, the synthesis strategy presented here could be considered as an effective methodology with mild conditions, simple operation and environmental safety.