Coaxial structured Bi2S3-SnS2-MWCNT hybrid nanocomposite with its improved thermoelectric properties

Bismuth(III) sulfide (Bi2S3), tin(IV) sulfide (SnS2), and a multi-walled carbon nanotube (MWCNT) are prepared as a hybrid composites (Bi2S3-SnS2-MWCNT) using a simple hydrothermal method. The as-prepared hybrid com-posite exhibit n-type thermoelectric (TE) characteristics and an enhanced power factor (PF) value. Bi2S3-SnS2 composites are anchored to the surface of MWCNT and form a coaxial structure. The nanostructure formation through bonding between these different materials is confirmed via scanning transmission electron microscopy (STEM) and X-ray photoelectron spectroscopy (XPS). The TE properties of the Bi2S3-SnS2-MWCNT composite is improved by changing the Bi2S3, SnS2 and MWCNT content. The maximum PF (-150.8 & mu;& BULL;W/m & BULL;K2) was obtained for Bi2S3-SnS2-MWCNT composite with Bi:Sn ratio of 7:3 and 2 wt% of CNT. The highest PF values were-34 and-58 times higher than the PF of Bi2S3 and SnS2 at room temperature. The synthesized Bi2S3-SnS2-MWCNT hybrid nanocomposite can provide important components for fabrication CNT-based TE composites with high conversion efficiency, further advancing TE device.

Automated summary

Bismuth(III) sulfide (Bi2S3), tin(IV) sulfide (SnS2), and a multi-walled carbon nanotube (MWCNT) are combined via a hydrothermal method to form a hybrid composite (Bi2S3-SnS2-MWCNT). The resulting composite exhibits n-type thermoelectric properties and an improved power factor (PF). The unique structure of the composite is confirmed through scanning transmission electron microscopy (STEM) and X-ray photoelectron spectroscopy (XPS). By optimizing the composition, the maximum PF of the composite is achieved, which is significantly higher than that of Bi2S3 and SnS2 alone at room temperature. This hybrid nanocomposite can serve as a crucial component for high-efficiency carbon nanotube-based thermoelectric composites, thus advancing thermoelectric device technology.