Exploring Functionalized Titania for Task Specific Application on Efficient Separation of Trivalent f-block Elements
Functionalized titania, obtained by grafting dipicolinic acid functionality, was explored for task specific application of highly efficient separation of trivalent f-block elements. Sorption mechanism, kinetcis and complexation have been investigated in detail. The chemisorption followed Langmiur isotherm and pseudo 2nd order rate kinetics. The Ti-2p3/2, O-1s and C-1s peaks in XPS spectra indicate the augmentation of functionalization, while Eu-4d peak at 136.5 eV confirms the complexation. EXAFS and XANES spectra for Eu L3-edge and Ti K-edge have been explored to characterize the sorbent and its complexation with Eu3+/Am3+. The peak at 1.9 Å was assigned to two oxygen coordination cells at 2.19 Å and 2.39 Å with approximately two and eight oxygen atoms, respectively, whereas peak at 2.5 Å relates to the coordination peak for Eu:DPA. The sorbent was found to have high radiological stability. DFT calculation optimized the structures of the Eu3+/Am3+ complexation with funcitionalized titania as M(NO3)3.L species. The Gibb's energy for aqueous phase complexation of Eu3+ and Am3+ was found to be -135.1 and -129.9 kcal/mol, respectively.