Influence of graphene oxide nanosheets and multi-walled carbon nanotubes on the thermoelectric and mechanical properties of Mg2(Si0.3Sn0.7)0.99Sb0.01

Abstract

Achieving the simultaneous improvement of thermoelectric and mechanical properties is of great significance for the application of thermoelectric materials. Here, we fabricate the bulks of Mg2(Si0.3Sn0.7)0.99Sb0.01 hybrid composites reinforced by graphene oxide nanosheets (GOs) and multi-walled carbon nanotubes (MWCNTs). The influences of GOs and MWCNTs on the thermoelectric and mechanical properties of the composites are characterized in detail. It is found that the hybrid composites exhibit obvious improvements in flexural strength and fracture toughness with respect to both the matrix and the samples reinforced by GOs or MWCNTs alone, owing to the remarkable synergistic effect of GOs and MWCNTs. Meanwhile, the dimensionless figures of merit are basically maintained or even slightly enhanced when dual reinforcements of GOs and MWCNTs are introduced. Our work provides a feasible path to obtain excellent mechanical and thermoelectric properties simultaneously.