Construction of novel stable surface ion-imprinted graphene aerogels for efficient and selective extraction of lithium ion

Selective extraction of lithium from salt lake brine has attracted widespread attention in order to meet the growing global demand for lithium. Due to the high Mg2+/Li+ ratio and low Li+ concentration in salt lake brine, extracting Li+ from salt lake brine is extremely challenging. Herein, a novel approach was employed using graphene oxide (GO) with abundant functional groups as the skeleton material, and trihydroxymethyl amino methane (Tris) as the pioneering reducing agent. Through the liquid phase self-assembly technology combined with surface modification, the Li+ imprinted three-dimensional block graphene aerogels (IDGAs) were successfully constructed under the assisted cross-linking effect of N,N-dimethylformamide (DMF). The IDGAs achieve good adsorption capacity (12.55 mg g-1), excellent regeneration performance, and comparatively high selectivity against Na+, K+, and Mg2+ of 4.75, 2.71, and 1.90, respectively. The exceptional properties of IDGAs can be attributed to the synergism resulting from the establishment of adsorption sites through the high specific surface area of the skeleton, as well as the selective recognition of Li+ by 2-hydroxymethyl-12-crown ether-4. Consequently, IDGAs represent a highly promising option for the efficient extraction of lithium from salt lake brine.