Unexpectedly efficient ion desorption of graphene–based materials

Abstract Ion desorption is extensive and extremely challenging for adsorbents with superior performance, for which conventional desorption methods involving high acid or base concentrations and large consumption of reagents are widely used. Here we experimentally demonstrated the unexpectedly rapid and efficient desorption of ions on magnetite–graphene oxide (M–GO) by adding trace amounts of Al3+. The corresponding concentration of Al3+ used was reduced by a factor of at least 250 compared with the conventional desorption method. The desorption rate reached up to ~ 97.0% for the typical radioactive and bivalent ions of Co2+, Mn2+, and Sr2+ within ~ 1 min. Importantly, we achieved the effective enrichment of radioactive 60Co, with the volume of the concentrated 60Co solution reduced by approximately 10 times compared with the initial solution. Density functional theory calculations revealed that the interaction of graphene with Al3+ was much stronger than that with divalent ions, yielding the adsorption probability of Al3+ superior to Co2+, Mn2+, and Sr2+ ions, suggesting that the proposed method could be used to enrich a wider range of ions in the fields of energy, biology, environment, and materials science.