Formation of lithium-selective sorbent in nanoreactors of the support based on titanium dioxide

Nanocomposite sorbents, which consist of anatase (binder) and lithium-containing spinel (selective towards Li + ions), where synthesized. Hydrated titanium dioxide was used as a matrix, where spinel was formed. Preliminarily it was shown that azeotropic drying affects the porous structure of titanium dioxide during its transformation from hydrogel to xerogel. The largest volume of mesopores has been found for the xerogel, which was dried with benzene. Mesopores perform a function of nanoreactors, where synthesis of Li-containing spinel occurs: their volume correlate with the amount of Li-containing spinel. Its composition is LiTi 2 O 4 or Li 4 Ti 5 O 12 . These phases are formed at 500 and 600–700 °C respectively. The sample containing the largest amount of spinel demonstrates the largest sorption capacity towards Li + ions (about 2 mmol g −1 ). The spinel nanoparticles are the selective constituents of the sorbents. Anatase performs a function of a binder. The sorbent of the optimal composition was used for multiple sorption–desorption. It is possible to increase the ratio of Li + and Na + ions in 1600 times comparing with that for sea water.