Chelation-Mediated Multicomponent Co-Assembly Strategy for Controllable Fabrication and Characterization of Titanium-Based Lithium-Ion Sieve with Selective Lithium Adsorption and Separation

To address the growing demand for efficient and green recovery of lithium resources, this study develops a co-assembly strategy mediated by Ti(IV)/Li+-polyacrylate complexes to fabricate mesoporous H2TiO3 lithium-ion sieve/carbon composites (H2TiO3@C), aiming to overcome the bottlenecks of conventional lithium-ion sieves such as large particle size, small specific surface area and limited adsorption capacity. Using tetrabutyl titanate (TBT, a Ti(IV) alkoxide precursor) and lithium acetate dihydrate as raw materials, a Ti(IV)/Li+-polyacrylate complex is employed as a precursor, in which the carboxylate groups of polyacrylic acid coordinate to the titanium centers while Li+ is ionically bound to the carboxylate groups; this complex co-assembles with poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) (PEO-PPO-PEO) triblock copolymer (Poloxamer 188) to prepare Li2TiO3 mesoporous carbon composites (Li2TiO3@C). The results demonstrate that when the mass ratio of Li2TiO3 to polyacrylic acid and Poloxamer 188 is 1:2:0.3, the prepared lithium-ion sieve particles exhibit uniform morphology, a large specific surface area, significantly enhanced adsorption capacity, high selectivity for lithium adsorption, and good cycling stability. This work integrates chelation-mediated precursor design with co-assembly chemistry, providing a feasible pathway for the fabrication of mesoporous lithium-ion sieves.