Enhanced Ion Current Rectification in 2D Graphene-Based Nanofluidic Devices.

摘要: Furthering the promise of graphene-based planar nanofluidic devices as flexible, robust, low cost, and facile large-scale alternatives to conventional nanochannels for ion transport, we show how nonlinear current-voltage (I-V) characteristics current rectification in these platforms can be enhanced by increasing system asymmetry. Asymmetric cuts made 2D multilayered graphene oxide film, example, introduces further asymmetry that natively inherent structurally symmetric system, which was recently shown responsible its behavior due diffusion boundary layer fore-aft Supported good agreement with theory, attribute enhancement decrease limiting positive bias state counter-ion trapping occurs within negatively charged sheets increased film permselectivity cross-section surface charge distribution is altered on one end; effects being sensitive electrolyte pH. Further, an imbalance pH or concentration microreservoirs flanking also increase hence rectification, addition displaying a host other phenomena associated I-V typical nanochannel electrokinetic systems.