Thermoelectric behavior of aerogels based on graphene and multi-walled carbon nanotube nanocomposites

In this work, we presented that the Seebeck coefficient and electrical conductivity can be increased simultaneously in aerogels based on graphene and multi-walled carbon nanotube (graphene-MWCNT) nanocomposites, and at the same time the thermal conductivity is depressed due to 3D porous skeleton structure. As a result, graphene-MWCNT aerogels possess ultra-low thermal conductivities (similar to 0.056 W m(-1) K-1) and apparent density (similar to 24 kg m(-3)), thereafter the figure of merit (ZT) of similar to 0.001 is achieved. Although the ZT value is too low for practical application as a thermoelectric (TE) material, the unique structure in this project provides a potential way to overcome the challenge in bulk semiconductors that increasing electrical conductivity generally leads to decreased Seebeck coefficient and enhanced thermal conductivity. (C) 2015 Elsevier Ltd. All rights reserved.