Many drugs, foods, and clothes are derived from natural
products;
however, little attention has been focused on natural-derived thermoelectric
(TE) materials. In this work, several natural amino acids are first
introduced to single-walled carbon nanotubes (SWCNTs) and a series
of environment-friendly n- and p-type freestanding SWCNT/amino acid
films are fabricated as potent TE materials. Among the composites,
SWCNT/histidine (His) and SWCNT/lysine (Lys) achieve excellent n-type
TE properties, with the highest power factors of 508.5 and 502.0 μW
m–1 K–2 at room temperature, respectively.
SWCNT/aspartic acid (Asp) displays p-type behaviors, with the highest
power factor of 221.6 μW m–1 K–2 at room temperature. Moreover, a TE device based on SWCNT/Lys and
SWCNT/Asp including five p–n junctions is fabricated. The high
open-circuit voltage (42.3 mV) and output power (4.3 μW) are
obtained at ΔT = 87 K. Given the excellent
TE performance, green composites based on natural-derived materials
can be the promising candidates for TE devices.