Origin of Ultrahigh Rectification in Polyelectrolyte Bilayers Modified Conical Nanopores
Journal
Journal of Physical Chemistry Letters
Journal Volume
12
Journal Issue
49
Pages
11858-11864
Date Issued
2021
Author(s)
Abstract
The switching of “ON” and “OFF” states of an ionic diode is investigated by considering a conical nanopore partially functionalized two polyelectrolyte (PE) layers via layer-by-layer deposition. Through observing the inversion of its rectification behavior, we demonstrate the function of the PE bilayers in ionic transport regulation. The ionic diode exhibits an ultrahigh ion rectification at a low level of pH. In an aqueous NaCl solution at pH 2, for example, the ratio of the current at “ON” state and that at “OFF” state can be about 800 and 200 for 1 and 100 mM, respectively. This remarkable gating behavior can be explained by the anion-pump-induced ion accumulation in the neutral region as well as the depletion zone at the interface. Our results further demonstrate the possibility of achieving an ultrahigh rectification in an ionic diode having a unipolar-like configuration. ? 2021 American Chemical Society
Subjects
Deposition
Diodes
Ions
Nanopores
Sodium chloride
'current
Aqueous NaCl solutions
Bi-layer
Conical nanopores
Functionalized
Ionic diodes
Ionic transports
Layer by layer deposition
Polyelectrolyte layers
Rectification behavior
Polyelectrolytes
Type
journal article