Multilayered graphene membrane as an experimental platform to probe nano-confined electrosorption

Multilayered graphene membranes (MGMs) with different packing densities were prepared and used as electrodes for supercapacitors to probe nano-confined electrosorption in porous carbon materials. The electrosorption capacity of MGMs was measured against an increasing operation rate in a series of aqueous solutions of monovalent ions. The nano-confinement effect was found prominent when the microscopic pore structure of the MGMs was controlled to be comparable to the size of hydrated ions being tested. The electrosorption capacity was found highly dependent on the type of ions. This study highlights the great potential of using easily available and structurally tunable graphene membranes as a model system to investigate fundamental problems relating to energy storage, membrane separation and nanofluidics.