H 2 TiO 3 composite adsorbent foam for efficient and continuous recovery of Li + from liquid resources

Metatitanic acid (H2TiO3) is a promising lithium ion sieve (LIS) that can supplant the traditional manganese oxide-based LIS. To materialize its potential use in continuous Li+ recovery, the H2TiO3 (HTO) was processed as pliant composite foams. Pre-synthesized HTO particles were incorporated in poly(vinyl alcohol) (PVA) matrix (HTO/PVA) via blending, lyophilisation, and chemical cross-linking. This approach ensured the high quality and convenient loading control of HTO in the foam. The composites were thoroughly characterized and evaluated in terms of Li+ adsorption performance and mechanical durability. At 200 wt% HTO loading, the HTO/PVA had minimal capacity loss (6%) and low retardation (8%) in Li+ uptake rate relative to the well-dispersed unsupported HTO powder. Such superior performance can be attributed to the high open pore network, uniform HTO distribution, and good wettability of the foam. Moreover, the composite maintained the Li+ selectivity of HTO in seawater suggesting minimal non-selective metal ion adsorption on the support matrix. The foam maintained its performance and mechanical integrity after several uses, demonstrating its high suitability for long-term application in Li+ mining from liquid resources like seawater.