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

摘要

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 mu m 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 Mg2+(0.03 mmol g(-1)) and Ca2+(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.