PbS/PbSe Hollow Spheres: Solvothermal Synthesis, Growth Mechanism, and Thermoelectric Transport Property

Uniform PbS/PbSe hollow spheres consisting of PbS and PbSe nanoparticles were synthesized by a facile solvothermal method in mixtures of ethylene glycol and tetrahydrofuran at 120 °C with the assistance of thioglycollic acid. Experimental parameters, such as reaction time, volume of thioglycollic acid, and volume ratio of ethylene glycol to tetrahydrofuran, played crucial roles in determining the morphologies and composites of the final products. Based on the electron microscope observations and X-ray diffraction (XRD) patterns, the reaction process and growth mechanism of such hierarchitectures were proposed. Nitrogen adsorption–desorption measurements and pore size distribution analysis revealed that the mesoporous existed in the product. Moreover, thermoelectric transport measurements demonstrated that the synergistic effects of PbS and PbSe would lead to enhancement of the electrical conductivity; the obtained binary phased PbS/PbSe hollow spheres had the maximum electrical conductivity and Seebeck coefficient of 22.1 S cm–1 and 323.3 μV/K, respectively, which were higher than those of pure PbSe nanoparticles.