posted on 2021-01-21, 19:06authored byYakang Jin, Ran Tao, Shuang Luo, Zhigang Li
In
this work, we investigate the thermoelectric properties of aqueous
KCl solutions confined in graphene nanochannels through molecular
dynamics simulations. The channel height H ranges
from 0.7 to 7.8 nm. It is found that the Seebeck coefficient, Se, and the figure of merit, ZT, of the KCl solution are highly sensitive to H when H is small. For the nanochannel
of H = 1.0 nm, Se = 30.6 mV/K and ZT = 4.6 at room temperature,
which are superior to most of the solid-state thermoelectric materials.
The remarkable thermoelectric properties in small channels are attributed
to the flow slip at the channel walls and the mean excess enthalpy
density of the solution, which is mainly from the potential energy
contribution. The molecular insight promotes the applications of nanofluidic
devices for thermal energy harvesting.