Hydrothermal synthesis and adsorption behavior of H(4)Ti(5)O(12) nanorods along [100] as lithium ion-sieves

The adsorption method is a promising route to recover Li(+) from waste lithium batteries and lithium-containing brines. To achieve this goal, it is vital to synthesize a stable and high adsorption capacity adsorbent. In this work, Li(4)Ti(5)O(12) nanorods are prepared by two hydrothermal processes followed by a calcination process. Then the prepared Li(4)Ti(5)O(12) nanorods are treated with different HCl concentrations to obtain a H(4)Ti(5)O(12) adsorbent with 5 μm length along the [100] direction. The maximum amount of extracted lithium can reach 90% and the extracted titanium only 2.5%. The batch adsorption experiments indicate that the H(4)Ti(5)O(12) nanorod maximum adsorption capacity can reach 23.20 mg g(−1) in 24 mM LiCl solution. The adsorption isotherms and kinetics fit a Langmuir model and pseudo-second-order model, respectively. Meanwhile, the real adsorption selectivity experiments show that the maximum Li(+) adsorption capacity reaches 1.99 mmol g(−1), which is far higher than Mg(2+) (0.03 mmol g(−1)) and Ca(2+) (0.02 mmol g(−1)), implying these nanorods have higher adsorption selectivity for Li(+) from Lagoco Salt Lake brine. The adsorption capacity for Li(+) remains 91% after five cycles. With the help of XPS analyses, the adsorption mechanism of Li(+) on the H(4)Ti(5)O(12) nanorods is an ion exchange reaction. Therefore, this nanorod adsorbent has a potential application for Li(+) recovery from aqueous lithium resources.