In Situ Oxidation Synthesis of p ‐Type Composite with Narrow‐Bandgap Small Organic Molecule Coating on Single‐Walled Carbon Nanotube: Flexible Film and Thermoelectric Performance

Abstract
Although composites of organic polymers or n‐type small molecule/carbon nanotube (CNT) have achieved significant advances in thermoelectric (TE) applications, p‐type TE composites of small organic molecules as thick surface coating layers on the surfaces of inorganic nanoparticles still remain a great challenge. Taking advantage of in situ oxidation reaction of thieno[3,4‐b]pyrazine (TP) into TP di‐N‐oxide (TPNO) on single‐walled CNT (SWCNT) surface, a novel synthesis strategy is proposed to achieve flexible films of TE composites with narrow‐bandgap (1.19 eV) small molecule coating on SWCNT surface. The TE performance can be effectively enhanced and conveniently tuned by poly(sodium‐p‐styrenesulfonate) content, TPNO/SWCNT mass ratio, and posttreatment by various polar solvents. The maximum of the composite power factor at room temperature is 29.4 ± 1.0 µW m−1 K−2. The work presents a way to achieve flexible films of p‐type small organic molecule/inorganic composites with clear surface coating morphology for TE application.

Thermoelectric composites of small molecule of thieno[3,4‐b]pyrazine di‐N‐oxides (TPNO) with narrow band‐gap and SWCNT are prepared by in situ oxidizing thieno[3,4‐b]pyrazine (TP) into TPNO as coating layer on the surface of SWCNT. The maximum power factor reaches 29.4 ± 1.0 μW m‐1 K‐2.

Source: Small - February 9, 2018 Category: Nanotechnology Authors: Caiyan Gao, Guangming Chen Tags: Communication Source Type: research