Light-Controlled Ionic Transport through Molybdenum Disulfide Membranes

In recent years, two-dimensional (2D) nanomaterials have been extensively explored in the field of nanofluidics due to their interconnected and well-controlled nanochannels. In particular, the investigation of 2D nanomaterials using their intrinsic properties for smart nanofluidics is receiving increased interest. Here, we report that MoS2 membranes can be used for light-controlled nanofluidic applications based on their photoelectrical properties. We show that the MoS2 membranes exhibit surface charge-governed ionic transport in NaCl and KCl solution without light illumination, while the ionic conductivity of the MoS2 membranes is up to 2 orders of magnitude higher at low concentration solution than that in bulk solution. We also show that the ionic conductivity of the membranes is enhanced under light illumination at 405 and 635 nm and reversible and stable switching of ionic current upon light illumination is observed. In addition, ionic current through membranes is enhanced by increasing light intensity. Therefore, our findings demonstrate that MoS2 membranes can be a potential platform for light-controlled nanofluidic applications.