18/07/2025
Scientific publication: Impact of precursor pretreatment on solid-state synthesized protonated lithium titanates and their subsequent lithium adsorption performance
The protonated product of lithium titanate (H2TiO3, HTO) is a promising adsorbent for lithium recovery from alkaline aqueous streams due to its high selectivity and cycling stability. This study investigates how precursor pretreatment influences the solid-state synthesis of its parent phase, monoclinic Li2TiO3 (LTO), and the resulting lithium adsorption performance of HTO. Multiple commercial TiO2 sources and pre-synthesis methodologies, including grinding, ball-milling, and ultrasonication in water, isopropanol, or ethanol, were evaluated for their impact on phase formation and textural properties. X-ray diffraction analysis revealed that high-energy ball-milling results in α-LTO after calcination, a phase that fails to produce effective Li-adsorbing HTO. In contrast, ultrasonication and conventional mixing preserve the desired monoclinic β-LTO structure. HTO derived from monoclinic LTOs exhibited superior performance, with adsorption capacities up to 25.84 mg g−1 and kinetic constants more than twice as high compared to untreated controls. All monoclinic HTOs followed pseudo-second-order kinetics and fit the Langmuir isotherm model, confirming monolayer adsorption. High lithium selectivity was maintained, as demonstrated by selectivity factors such as = 660, and = 2927 for HTOs obtained via ultrasonication in water. In contrast, materials derived from cubic LTO showed negligible lithium selectivity. Notably, HTO prepared via ultrasonication in water matched or exceeded solvent-based methods in performance, offering a more sustainable and scalable processing route. Repeated adsorption-desorption cycles using synthetic brines demonstrated consistent lithium recovery of approximately 30 % per cycle, and minimal titanium leaching. These findings underscore the critical role of precursor pre-treatment in tailoring the properties of lithium sorbents via solid-state synthesis, and identify ultrasonication in water as a scalable, eco-friendly approach to produce high-performance HTO.
Access the entire publication in Ceramics International Journal