Electrical, luminescence, and microwave-assisted reduction behaviour of alkali vs. alkaline earth metal ion-modified graphene oxide membranes

Ions are often introduced into graphene oxide (GO) membranes during their preparation and application, which may lead to changes in their properties. In this study, GO membranes regulated by ions were prepared by incorporating alkali and alkaline earth metals. We found that the introduction of different ions led to opposite changes in the electrical properties of the reduced GO (RGO) membranes. The introduction of alkali metal ions improves their conductivity, whereas the introduction of alkaline earth metal ions results in a decrease in their conductivity. Furthermore, we found that the introduction of ions resulted in significantly different changes in the luminescence spectra, which could be used to detect alkali and alkaline earth metal ions. In addition, the introduction of alkali metal and alkaline earth metal ions resulted in significantly different changes in the luminescence spectra and microwave reduction effect of the RGO membranes. The introduction of alkaline earth metal ions was more helpful for the removal of oxygen-containing groups and the restoration of the graphene lattice structure when exposed to microwave irradiation. These results suggest that the properties of GO membranes can be regulated by regulating the introduction of ions, and these findings have potentially important applications in the preparation and application of GO membranes and ion detection.