Construction of S-doped H2TiO3-Ferrite magnetic ion sieve for improved extracting lithium

Titanium-based lithium-ion sieves (LISs) have attracted considerable attention because of their superior adsorption capacity and cycling stability in lithium ion extraction. In this paper, an S-doped H 2 TiO 3 -ferrite ion sieve was successfully synthesized through co-precipitation scheme. The recycling problem of lithium ion sieve powder was effectively solved by utilizing its magnetic separation property. LTSO-Ferrite was prepared in one step using a high-temperature solid-phase method, with an optimal molar ratio of FeCl 2 : TiS 2 : TiO 2 = 0.2: 0.2: 1. The adsorption capacity of S-doped H 2 TiO 3 -Ferrite (HTSO-Ferrite) reached 43.02 mg/g, and the magnetization value was 4.81 emu/g. The adsorption energy and structure of Li + on LTSO-Ferrite were determined using density functional theory (DFT) to assess the feasibility of lithium absorption. The adsorption behavior of LTSO-Ferrite toward Li + followed the Langmuir isotherm and pseudo-second-order kinetic models, indicating that the adsorption was endothermic and spontaneous. LTSO-Ferrite exhibited good selectivity for heteroatoms in simulated brine. Magnetic recovery rate remained at 98 % with an adsorption capacity of 36.16 mg/g after five cycles, which is 84 % of its maximum adsorption capacity. LTSO-Ferrite exhibited magnetic separation properties, offering a promising approach for developing lithium adsorbents for extraction from unsalted lake brine.