Highly hydrophilic H2TiO3 ion sieve with neodymium (Nd) doping enables fast and high-efficiency Li extraction.

[Display omitted] • 1% Nd doping metatitanic acid H 2 TiO 3 (HTO) is synthesized for the first time. • Nd-doped HTO has a more hydrophilic surface with a contact angle of 16.5°. • Nd-doped HTO reduces adsorption equilibrium time by half to 4 h. • Nd-doped HTO increases adsorption capacity by 12.5% compared to the undoped one. • Nd-doped HTO undergoes 8 cycles with merely 0.14% of titanium dissolution loss. The metatitanic acid H 2 TiO 3 (HTO) with high selectivity shows potential in lithium extraction from salt lake brine. Nevertheless, the sluggish adsorption kinetics and unsatisfying actual adsorption capacity hinder H 2 TiO 3 industrial application. Herein, a rare earth element Nd-doped H 2 TiO 3 (Nd-HTO-1 %) was synthesized. The crystallinity, morphology, hydrophilicity, adsorption property and mechanism of Nd-HTO-1 % were systematically characterized by a series of techniques. Interestingly, Nd-doping promotes the generation of oxygen vacancies, thereby increasing the density of surface hydroxyl groups and making the surface high-hydrophilic and particle size decreased. After 1 % Nd-doping, high-hydrophilic HTO was obtained with a contact angle of 16.5°. The adsorption capacity of Nd-HTO-1 % increased by 12.5 % compared with HTO, and the equilibrium time of adsorption reduced by half to 4 h. After eight cycles, Nd-HTO-1 % still showed a considerable adsorption capacity of 39.69 mg·g−1. In the meantime, the dissolution loss of titanium is merely 0.14 %, showing excellent cycling stability. Combined with the considerable selectivity exhibiting in Qarhan salt lake brine, it demonstrates potential in utilization of Nd-doped H 2 TiO 3 for lithium extraction from salt lake brine. [ABSTRACT FROM AUTHOR]

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