Enhanced Thermoelectric Performance of Novel Reaction Condition-Induced Bi₂S₃-Bi Nanocomposites

Abstract

This is the first report on the enhanced thermoelectric (TE) properties of novel reaction-temperature (T Re ) and duration-induced Bi 2 S 3 -Bi nanocomposites synthesized using a facile one-step polyol method. They are well characterized as nanorod composites of orthorhombic Bi 2 S 3 and rhombohedral Bi phases in which the latter coats the former forming Bi 2 S 3 -Bi core− shell-like structures along with independent Bi nanoparticles. A very significant observation is the systematic reduction in electrical resistivity ρ with a whopping 7 orders of magnitude (∼10 7 ) with just reaction temperature and duration increase, revealing a promising approach for the reduction of ρ of this highly resistive chalcogenide and hence resolving the earlier obstacles for its thermoelectric application potentials in the past few decades. Most astonishingly, a TE power factor at 300 K of the highest Bi content nanocomposite pellet, made at 27 °C using ∼900 MPa pressure, is 3 orders of magnitude greater than that of hot-pressed Bi 2 S 3 . Its highest ZT at 325 K of 0.006 is over twice of that of similarly prepared CuS or Ag 2 S-based nanocomposites. A significantly improved TE performance potential near 300 K is demonstrated for these toxic-free and rare-earth element-free TE nanocomposites, making the present synthesis method as a pioneering approach for developing enhanced thermoelectric properties of Bi 2 S 3 -based materials without extra sintering steps.

Compositional engineering of metal-xanthate precursors toward (Bi1−xSbx)2S3 (0 ≤ x ≤ 0.05) films with enhanced room temperature thermoelectric performance

“…Therefore, we adopted composition engineering using a chalcogenide metal-xanthate precursor (bismuth(III) ethylxanthate) to prepare high-quality Bi 2 S 3 films on soda-lime glass via spin-coating and post-annealing. The characterization of these as-deposition Bi 2 S 3 thin films showed a higher Seebeck coefficient of À388.33 mV K À1 than that previously reported for both thinfilm 50 and bulk materials [51][52][53] at RT. The P.F.…”

Improved Thermoelectric Figure of Merit in Polyol Method-Prepared Cu1–xBixS (x ≤ 0.06) Nanosheets

“…This is a 6 times increase over CS1 (ZT = 0.003). Although this ZT value is not relatively high for TE applications due to room-temperature pelletization, it is 6 times higher than diethylene glycol-synthesized Ag-doped CuS NPs 3 because of annealing at 250 °C and thrice that of similar less toxic and naturally abundant solution-grown Bi 2 S 3 -Bi nanocomposites . Hence, we can expect higher ZT values for these materials when prepared using spark plasma sintering.…”

Bismuth Sulfide Strongly Coupled to Functionalized MWNTs Hybrids with Improved Thermoelectric Properties

“…The BiO peak in the O 1s region has also been observed to be sensitive to other factors, such as reduced metal content on the surface of the material. [ 18,36,37 ] At this time, the appearance of the peak at 532 eV in the O 1s region of the composites is attributed to the formation of interfacial BiO bonds between the Bi 2 S 3 and oxygen‐containing functional groups on the MWNT. Intensities at higher B.E.…”