Selective Transport Properties Of Graphene Oxide Membranes For Various Cations Observed In Situ Using Quartz Crystal Microbalance

Graphene oxide membranes (GOMs) have become promising materials in several applications, such as nano-fluidic devices, ion sieving, biosensors, lithium-based batteries, and supercapacitors. Understanding the transport properties of cations in the interlayer spacings between Graphene oxide (GO) sheets is crucial for developing GOMs for these applications. In this study, we used an impedance-based quartz crystal microbalance (QCM) to detect the in situ structural adaptivity of interlayer spacings and cation behaviors in GOMs for responses to cation adsorption. The results showed that different cations (K+, Na+, Li+, or Mg2+) could cause various marked changes in GOM properties, including dissipation, mass, and viscoelastic characteristics, thereby revealing significant selective GOM transport properties, which indicated the excellent cation sensing and identification ability of GOMs. The presence of K+ resulted in a decrease in the mass and dissipation properties of GOMs, as obtained from the Delta f-Delta R response analysis, which demonstrated the sieving effect of the cations of the KCl-controlled GOMs in our previous work. Notably, Li+ has superior transport and adsorption performances compared to other cations. We believe that these findings might provide a novel mute in cation sensing, identification analysis, or the extraction of cations.