Abstract
A simple biomolecule-assisted hydrothermal approach has been developed for the fabrication of
Bi2Te3 thermoelectric nanomaterials. The product has a nanostring-cluster hierarchical structure which is composed
of ordered and aligned platelet-like crystals. The platelets are100 nm in diameter and only10 nm thick
even though a high reaction temperature of 220 °C and a long reaction time of 24 h were applied to prepare the
sample. The growth of the Bi2Te3 hierarchical structure appears to be a self-assembly process. Initially, Te nanorods
are formed using alginic acid as both reductant and template. Subsequently, Bi2Te3 grows in a certain direction
on the surface of the Te rods, resulting in the nanostring structure. The nanostrings further recombine side-byside
with each other to achieve the ordered nanostring clusters. The particle size and morphology can be controlled
by adjusting the concentration of NaOH, which plays a crucial role on the formation mechanism of Bi2Te3. An
even smaller polycrystalline Bi2Te3 superstructure composed of polycrystalline nanorods with some nanoplatelets
attached to the nanorods is achieved at lower NaOH concentration. The room temperature thermoelectric
properties have been evaluated with an average Seebeck coefficient of172 V K1, an electrical resistivity of
1.97103m, and a thermal conductivity of 0.29 W m1 K1
Bi2Te3 thermoelectric nanomaterials. The product has a nanostring-cluster hierarchical structure which is composed
of ordered and aligned platelet-like crystals. The platelets are100 nm in diameter and only10 nm thick
even though a high reaction temperature of 220 °C and a long reaction time of 24 h were applied to prepare the
sample. The growth of the Bi2Te3 hierarchical structure appears to be a self-assembly process. Initially, Te nanorods
are formed using alginic acid as both reductant and template. Subsequently, Bi2Te3 grows in a certain direction
on the surface of the Te rods, resulting in the nanostring structure. The nanostrings further recombine side-byside
with each other to achieve the ordered nanostring clusters. The particle size and morphology can be controlled
by adjusting the concentration of NaOH, which plays a crucial role on the formation mechanism of Bi2Te3. An
even smaller polycrystalline Bi2Te3 superstructure composed of polycrystalline nanorods with some nanoplatelets
attached to the nanorods is achieved at lower NaOH concentration. The room temperature thermoelectric
properties have been evaluated with an average Seebeck coefficient of172 V K1, an electrical resistivity of
1.97103m, and a thermal conductivity of 0.29 W m1 K1
| Originalsprog | Engelsk |
|---|---|
| Tidsskrift | A C S Nano |
| Vol/bind | 4 |
| Nummer | 5 |
| Sider (fra-til) | 2523–2530 |
| Antal sider | 8 |
| ISSN | 1936-0851 |
| Status | Udgivet - 2010 |