Boosting the Thermoelectric Performance of N-Type Bi2s3 by Compositing Rgo

The construction of nanocomposite structures can effectively reduce the lattice thermal conductivity of thermoelectric materials, which are considered an essential technique to improve the thermoelectric figure of merit of thermoelectric materials. Herein, we prepared a series of Bi2S3 +xml reduced graphene oxide (rGO)(x = 5 ml, 10 ml, 15 ml, 20 ml) nanocomposite thermoelectric materials by combining simple hydrothermal synthesis techniques and tubular sintering techniques. The rGO is uniformly dispersed in the precursor solution and tightly bound in the Bi2S3 matrix, which significantly reduces the thermal conductivity of the matrix material. The total thermal conductivity(κ) of the Bi2S3/rGO (20 ml) nanocomposite is as low as 0.12 W·K−1·m−1 at 578 K, which is nearly 69% lower than that of the pure Bi2S3. In addition, the conductivity of Bi2S3/rGO (10 ml) nanocomposites above 450 K is better than that of the pure Bi2S3, which indicates that adjusting the content of rGO can optimize the conductivity of Bi2S3 to a certain extent. At 577 K, the ZT of Bi2S3/rGO (10 ml) nanocomposite can reach 0.22, which is 46% higher than that of pure Bi2S3. This study utilizes hydrothermal synthesis techniques and tubular sintering techniques to tune the structure of composites at the nanoscale, providing a new approach for optimizing the thermoelectric properties of Bi2S3.