Prelithiation-derived hierarchical TiO2 sieve with metal-organic framework gate for selective lithium recovery

Abstract

Sustainable lithium supply significantly matters the healthy development of electric vehicles markets. Selective adsorption plays an important role in aqueous lithium recovery due to low energy consumption and easy processing. We here report a prelithiation concept to generate active Li+ sites in TiO2 forming LixTiO2 at a mild temperature for lithium recovery. A hollow protonated LixTiO2 matrix with nanosheets surface was built to provide abundant active sites for specific Li+ capture with fast matter transfer. And a biomimetic metal–organic framework (ZIF-8) gate layer, acting as Li+ channel, was engineered to regulate cation solvation structure for selective transport of Li+. Consequently, the resultant TiO2-based hybrid lithium-ion sieve demonstrates fast and homogenous Li+ chemisorption with a high Li+ uptake capacity (∼14 mg g−1 for 24 h at pH = 12), high Li+ selectivity against competing cations in both simulated and natural brine, and acceptable reusability in simulated brine, indicating further application potential.