Graphene oxide embedded in Bi2S3 nanosheets by hydrothermal method to enhance thermoelectric performance

Abstract

Bi2S3 is an inexpensive and non-toxic thermoelectric material with high Seebeck coefficient and low thermal conductivity, which makes it have broad development prospects in the field of thermoelectric materials. In this work, we successfully synthesized Bi2S3/graphene oxide (GO) hybrid nanosheets by a simple hydrothermal synthesis method. Due to the unique structure of the two-dimensional nanomaterial GO, it can be uniformly embedded in the Bi2S3nanosheet matrix. The total thermal conductivity of Bi2S3/GO hybrid nanosheets is astonishingly low as 0.32Wm−1K−1 at 619K, which is 13% lower than that of pure Bi2S3. In addition, the thermoelectric performance of Bi2S3/GO hybrid nanostructures were further improved by changing the doping amount of GO. At 300–650K, the maximum thermoelectric figure of merit (ZT) of Bi2S3/GO(0.5 wt%) is 0.17, and its ZT below 550K is higher than that of pure phase Bi2S3. Bi2S3/GO composites were synthesized by an inexpensive and simple experimental method, which provides a new strategy for optimizing the thermoelectric properties of Bi2S3.