Enhanced Thermoelectric Properties of Bilayer-Like Structural Graphene Quantum Dots/Single-Walled Carbon Nanotubes Hybrids
Jun-An Yao, Xiaoxi Peng, Zhekun Liu, Yunfei Zhang, Ping Fu, Hui Li, Zhidong Lin, Feipeng Du
Abstract
In order to improve the thermoelectric properties of single-walled carbon nanotubes (SWCNTs), bilayer-like structures of graphene quantum dots (GQDs) and SWCNTs films (b-GQDs/SWCNTs) were prepared by directly coating GQDs on the surface of SWCNTs films. Compared to pristine SWCNT films (p-SWCNTs), the electrical conductivity of b-GQDs/SWCNTs increased while their Seebeck coefficient decreased. The special interface structure of GQDs and SWCNTs can not only improve carrier transport to increase electrical conductivity but also scatter phonons to reduce thermal conductivity. A maximum power factor (PF) of 51.2 μW·m–1·K–2 is obtained at 298 K for the b-GQDs/SWCNTs (2:100), which is higher than the PF of 40.9 μW·m–1·K–2 by p-SWCNTs. Incorporation of GQDs shows an obvious improvement in power factor and a significant reduction in the thermal conductivity for SWCNTs, and thus, preparation of b-GQDs/SWCNTs provides a new strategy to enhance the thermoelectric properties of SWCNTs-based materials.