High-efficiency lithium-ion sieves synthesized via hydrothermal-roasting method

Abstract

Titanium-based ion sieves have consistently demonstrated good adsorption performance in the adsorption of Li⁺. However, the slow adsorption rate has limited their further industrial application. In this study, the synthesis of ion sieves by a simple hydrothermal-roasting method using surfactant modification. Based on preliminary experiments, ion sieves with excellent adsorption properties can be synthesized at 450 °C. Through characterization analysis such as SEM and contact Angle measurement, the sample was found to have a uniform shape and size nanostructure. H₂TiO₃ (HTO-1) had good hydrophilic properties, providing more adsorption sites for Li⁺ adsorption and improving the adsorption rate of ion sieves. Through the adsorption experiment (initial Li⁺ concentrations: 50, 100, 200, 300 mg g-1, T = 35 °C, pH = 12.3), HTO-1 could reach more than 80 % of the equilibrium adsorption capacity within 15 min, and the maximum adsorption capacity reached 87.5 mg g⁻¹. The pseudo-second-order kinetic and Langmuir models proved that the material underwent a monolayer chemisorption process. HTO-1 had excellent selectivity for Li⁺ in various ionic solutions. After five cycles of adsorption experiments, the adsorption capacity remained above 90 % of the initial value and the dissolution loss rate of Ti⁴⁺ remained below 0.3 %, the material shows good structural stability compared to other ion sieves. This work provides a reference for preparing lithium-ion sieves with better performance and higher efficiency.