A catalyst-free new polyol method synthesized hot-pressed Cu-doped Bi2S3 nanorods and their thermoelectric properties

• Published in: Nano research Vol. 9; no. 11; pp. 3291 - 3304
• Main Authors: Tarachand, Sharma, Vikash, Bhatt, Ranu, Ganesan, Vedachalaiyer, Okram, Gunadhor Singh
• Format: Journal Article
• Language: English
• Published: Beijing Tsinghua University Press 01.11.2016; Springer Nature B.V
• Subjects: Atomic force microscopy; Atomic structure; Atomic/Molecular Structure and Spectra; Bi2S3; Biomedicine; Biotechnology; Bismuth sulfides; Catalysis; Catalysts; Chemical synthesis; Chemistry and Materials Science; Condensed Matter Physics; Copper; Crystal structure; Data analysis; Data processing; Diffraction; Electron microscopy; Elongation; Figure of merit; Hot pressing; Image transmission; Light scattering; Materials Science; Microscopy; Nanoparticles; Nanorods; Nanotechnology; Photoelectron spectroscopy; Photon correlation spectroscopy; Research Article; Rietveld; Thermoelectricity; Transmission electron microscopy; X ray analysis; X-ray diffraction; X-rays; X射线光电子能谱; 多元醇法; 无催化剂; 热压; 热电性能; 纳米棒; S; polyol; nanorods; thermoelectrics; Bi
• ISSN: 1998-0124; 1998-0000
• DOI: 10.1007/s12274-016-1207-6

This is the first report on the thermoelectric properties of a catalyst-free polyol method used to prepare stoichiometric Bi2-xCuxS3 samples, x = 0.1, 0.2, 0.3, 0.4, via hot pressing. Various systematic approaches to arrive at in their stoichiometric compositions are explored precisely with introduction of excess precursor of S. X-ray diffraction data analysis using Rietveld refinement confirms a polyhedral orthorhombic crystal structure with a space group Pnma, in contrast to Pbnm reported earlier. Raman data further substantiates this. X-ray photoelectron spectroscopy confirms the valence states of the constituent elements （Bi^3＋, Cu^2＋, and S^2-） and energy dispersive X-ray analysis corroborates their compositions. The particle sizes of the pure Bi2S3 nanoparticles were 20, 35, and 82 nm as determined from the Scherrer formula, atomic force microscopy, and dynamic light scattering, respectively. Their transmission electron microscopy image shows rod-like nanostructures elongated in the 〈010〉 direction with an average diameter of 23 nm and a length of several hundreds of nanometers. A 34% improvement in the thermoelectric figure of merit is observed for Bi.6Cu0.4S3 as compared to pure Bi2S3 at 300 K.