Preparation and thermoelectric properties of SiO2/β-Zn4Sb3 nanocomposite materials

Abstract

A series of SiO 2 /β-Zn 4 Sb 3 core-shell composite particles with 3, 6, 9, and 12 nm of SiO 2 shell in thickness were prepared by coatingβ-Zn 4 Sb 3 microparticles with SiO 2 nanoparticles formed by hydrolyzing the tetraethoxysilane in alcohol-alkali-water solution. SiO 2 /β-Zn 4 Sb 3 nanocomposite thermoelectric materials were fabricated with these core-shell composite particles by spark plasma sintering (SPS) method. Microstructure, phase composition, and thermoelectric properties of SiO 2 /β-Zn 4 Sb 3 nanocomposite thermoelectric materials were systemically investigated. The results show thatβ-Zn 4 Sb 3 microparticles are uniformly coated by SiO 2 nanoparticles, and no any phase transformation reaction takes place during SPS process. The electrical and thermal conductivity gradually decreases, and the Seebeck coefficient increases compared to that ofβ-Zn 4 Sb 3 bulk material, but the increment of Seebeck coefficient in high temperature range remarkably increases. The thermal conductivity of SiO 2 /β-Zn 4 Sb 3 nanocomposite material with 12 nm of SiO 2 shell is the lowest and only 0.56 W·m -1 ·K -1 at 460 K. As a result, the ZT value of the SiO 2 /β-Zn 4 Sb 3 nanocomposite material reaches 0.87 at 700 K and increases by 30%.

Evolution of Thermoelectric Properties of Zn4Sb3 Prepared by Mechanical Alloying and Different Consolidation Routes

“…In terms of doping Al element, the Seebeck coefficient shows a similar trend as that of doping Cu. The thermal conductivity is also lower than that of Zn 4 Sb 3 as expected by Cui et al Ruan et al [35] reported that for Zn 4 Sb 3 coated with a layer of SiO 2 film, the results showed that the coating does not induce phase transformation, but SiO 2 film can effectively reduce thermal conductivity and increase the ZT value. …”

Study on Special Thermal-Insulation Masonry Mortar for the North Cold Regions Autoclaved Aerated Concrete

“…Influence of Redispersible Polymer Powder on Thermal-insulation Mortar Properties. The main purpose of mixing with redispersible polymer powder is to improve the workability and bonding strength of mortar [2][3]. It can be seen from Fig.…”

Advances in Thermoelectric Energy Conversion Nanocomposites

“…It is reported that Ba y Co 4 Sb 12 nanocomposites with dispersed fullerene or barium fulleride have been successfully fabricated by the SPS and solid state reaction (Shi et al, 2007). Also, SiO 2 /β-Zn 4 Sb 3 core-shell nanocomposite particles with the low thermal conductivity were synthesized by SPS method (Ruan & Xiao, 2007). Moreover, CoSb 3-x Te x skutterudite polycrystals were synthesized by SPS along with mechanical alloying (Liu et al, 2007).…”

“…β phase Zn 4 Sb 3 is a structurally disordered intermetallic compound at moderate temperature range 450 K-650 K. So β phase Zn 4 Sb 3 is a promisng nanocomposite material which possesses potential low thermal conductivity. (Ruan & Xiao, 2007).…”