ja6b11100_si_001.pdf (1.04 MB)
High and Stable Ionic Conductivity in 2D Nanofluidic Ion Channels between Boron Nitride Layers
journal contribution
posted on 2017-04-18, 00:00 authored by Si Qin, Dan Liu, Guang Wang, David Portehault, Christopher J. Garvey, Yury Gogotsi, Weiwei Lei, Ying ChenAchieving a high rate of ionic transport
through porous membranes
and ionic channels is important in numerous applications ranging from
energy storage to water desalination, but it still remains a challenge.
Herein we show that ions can quickly pass through interlayer spaces
in hydrated boron nitride (BN) membranes. Measurements of surface-charge
governed ionic currents between BN nanosheets in a variety of salt
solutions (KCl, NaCl and CaCl2) at low salt concentrations
(<10–4 M) showed several orders of magnitude
higher ionic conductivity compared to that of the bulk solution. Moreover,
due to the outstanding chemical and thermal stability of BN, the ionic
conduits remain fully functional at temperatures up to 90 °C.
The BN conduits can operate in acidic and basic environments and do
not degrade after immersing in solutions with extreme pH (pH ∼
0 or 14) for 1 week. Those excellent properties make the BN ionic
conduits attractive for applications in nanofluidic devices and membrane
separation.