Selective adsorption of cesium (I) from water by Prussian blue analogues anchored on 3D reduced graphene oxide aerogel

Abstract

In this paper, Prussian blue analogues (PBAs) anchored on 3D reduced graphene aerogel (denoted as 3D rGO/PBAs) was prepared, characterized and applied for adsorption of Cs(I) from aqueous solution. The results showed that 3D rGO/PBAs had high specific surface and good hydrophilic property, which was beneficial to the exposure of adsorptive sites and the transfer of adsorbates. The composite exhibited excellent adsorption performance towards Cs(I), and the maximum adsorption capacity was up to 204.9 mg/g, higher than most of reported values. The pseudo second-order kinetic model (R2 = 0.999) and the Langmuir isotherm model (R2 = 0.997) could fit the adsorption process well, suggesting the nature of homogeneous monolayer chemisorption. High distribution coefficients (kd) (2.8 × 104 to 5.8 × 104 mL/g), revealed that the composite had good selectivity. Ion-exchange, ion trapping and the complexation interaction might be involved in the process of cesium adsorption, in which ion-exchange may be dominant by characterization results.