Chemical state of U(VI) and Nd(III) confined between graphene oxide sheets.

This project aims at revealing the mechanism of U(VI) and Nd(III) sorption by multi-layered graphene oxide (GO). The chemical state of these elements confined between graphene oxide sheets will be studied High energy resolution fluorescence detection XANES (HERFD-XANES) and Extended X-ray absorption fine-structure (EXAFS) methods. Two types of graphite oxide materials (synthesized by Brodie and Hummers methods) will be studied testing relations between sorption capacity, chemical state of confined elements and inter-layer distance provided by swelling of these materials in water. The swelling results in formation of 2D “channels” with width of 3Å-7Å depending on the type of material, thus providing possibility for selective sorption related to the size of hydrated ions. It is expected that the data collected during experiments will contribute to understanding the mechanism of U(VI) and Nd(III) sorption inside of confined space of inter-layers.