Green synthesis of air-stable tellurium nanowires via biomolecule-assisted hydrothermal for thermoelectrics

Abstract

Tellurium nanowires (Te NWs) have been widely investigated in energy generators, photoelectric devices, sensors and chemical templates due to their interesting properties. However, these promising applications can be critically hindered by the inferior electrical conductivity of Te NWs and the ungreen and high energy consumption of the synthesis process. Herein, we suggest a feasible and eco-friendly strategy to synthesize Te NWs via a hydrothermal process by employing the biomolecule glucose as the reductant. The suggested strategy not only successfully avoided the use of toxic and harsh reductants and additional surfactants but also obtained Te NWs, even at low reaction temperatures. Moreover, the synthesized Te NWs presented a high electrical conductivity of 8.44 S cm⁻¹ by optimizing the reaction conditions, and a large power factor of 97.3 μW m⁻¹ K⁻² can be obtained after annealing. Combining the variable range hopping (VRH) model with the carrier transport parameters, the PVP surfactant-weakened carrier transporting mechanism was proposed. With the as-assembled thermoelectric generator, a promising output voltage of 231 mV can be realized when the temperature difference is 80 K. The strategy shows a novel design for synthesizing highly conductive Te NWs in an eco-friendly process and presents a promising Te NWs-based thermoelectric material.