The innovation engine for new materials

Pan Hu

University: 

Fudan University

Major: 

Chemistry

Mentor(s): 

Yichi Zhang

Faculty Sponsor(s): 

Professor Galen Stucky

Faculty Sponsor's Department: 

Chemistry and Biochemistry

Project Title: 

The Thermoelectric Properties Of Graphene Incorporated Bismuth Telluride Nanocomposite

Project Description: 

Thermoelectric (TE) materials exhibit a direct conversion of temperature gradient and electric potential. These materials can be used as environmentally friendly power generators or Peltier coolers. The figure of merit (zT) is defined to evaluate conversion efficiency between temperature gradient and electric potential. And Bi2Te3 semiconductor is a typical high zT TE in low temperature ranges (r.t. to 500 K) and the zT may be considerably enhanced using adulterating materials with high electrical conductivity (i.e. one dimensional carbon nanotubes)1. As a novel two-dimensional carbon material, graphene has a high electrical conductivity. Hence, the primary goal is to develop a facile and scalable synthesis method to approach a novel Bi2Te3 and graphene nanocomposite. Starting from Bi3+, HTeO2+ and graphene oxide aqueous solution, we obtained this homogeneous nanocomposite via pH adjustment and solid state reduction by hydrogen. XRD, SEM, TEM, EDX (Energy-dispersive X-ray spectroscopy) and ICP-AES (Inductively Coupled Plasma-Atomic Emission Spectroscopy) were used to reveal the crystal information, microstructures and chemical composition respectively. This homogeneous dual phase nanocomposite is ready to be hot pressed into condense pellet for the purpose of Seebeck coefficient and electrical conductivity measurements. We expect the figure of merit of the dual phase nanocomposite to be enhanced as compared to Bi2Te3. In summary, a novel thermoelectric nanocomposite is synthesized via a facile, tunable and scalable approach. 1Nano Lett., Vol. 8, No. 12, 2008.4428