Table_1_Synthesis and Thermoelectric Characterization of Lead Telluride Hollow Nanofibers.DOCX

Lead telluride (PbTe) nanofibers were fabricated by galvanic displacement of electrospun cobalt nanofibers where their composition and morphology were altered by adjusting the electrolyte composition and diameter of sacrificial cobalt nanofibers. By employing Co instead of Ni as the sacrificial material, residue-free PbTe nanofibers were synthesized. The Pb content of the PbTe nanofibers was slightly affected by the Pb2+ concentration in the electrolyte, while the average outer diameter increased with Pb2+ concentration. The surface morphology of PbTe nanofibers was strongly dependent on the diameter of sacrificial nanofibers where it altered from smooth to rough surface as the Pb2+ concentration increased. Some of thermoelectric properties [i.e., thermopower (S) and electrical conductivity(σ)] were systematically measured as a function of temperature. Energy barrier height (Eb) was found to be one of the key factors affecting the thermoelectric properties–that is, higher energy barrier heights increased the Seebeck coefficient, but lowered the electrical conductivity.本研究通过对静电纺丝钴纳米纤维开展原电池置换反应，制备碲化铅（PbTe）纳米纤维；通过调控电解液组分与牺牲型钴纳米纤维的直径，可调节所得产物的组分与形貌。相较于以镍（Ni）作为牺牲材料，选用钴（Co）作为牺牲材料时，可合成无残留的PbTe纳米纤维。PbTe纳米纤维中的铅含量受电解液中铅离子（Pb²+）浓度的影响较小，其平均外径则随Pb²+浓度升高而增大。PbTe纳米纤维的表面形貌强烈依赖于牺牲型纳米纤维的直径，且随着Pb²+浓度升高，其表面可由光滑转为粗糙。本研究系统测量了部分热电性能指标——即热功率（S）与电导率（σ）——随温度的变化规律。研究发现，势垒高度（Eb）是影响热电性能的关键因素之一：势垒高度越高，塞贝克系数越大，但电导率却越低。