Minerals Modulate Lithium Ion Sieve for Efficient Lithium Extraction

Abstract

Efficient lithium recovery from salt-lake brines is vital for lithium-resource supply. Nevertheless, practical application of titanium-based H2TiO3 (HTO) ion sieves is limited by insufficient adsorption performance. Herein, a high-performance HTO adsorbent (HTO-VMT) was fabricated using vermiculite to regulate the spatial coordination environment and surface hydrophilicity of HTO. Theoretical calculations and experimental analysis reveal that vermiculite, as a Si source and support for HTO, enables interfacial Si migration through isovalent substitution of Ti atoms, leading to atomic-level integration into the HTO crystal lattice. The Si substitution results in an upward shift of the p-band center of O of HTO, which enhanced hybridizations between Li 2s and O 2p orbitals, thus accelerating lithium adsorption rates in the surface diffusion phase. Thanks to an optimal coordination structure and surface hydrophilicity, HTO-VMT exhibits exceptional lithium extraction performance, surpassing state-of-the-art counterparts. This work provides design insights for Li-selective adsorbents via mineral-mediated atomic-scale coordination modulation.