Lithium adsorption from brine by iron-doped titanium lithium ion sieves

Iron-doped lithium titanium oxides were prepared via a solid-state reaction and transformed into lithium ion sieves by acid treatment. Scanning electron microscopy, X-ray photoelectron spectroscopy, and transmission electron microscopy showed that Fe3+ was doped into the Ti–O lattice and Ti–Fe–O bonds were formed. Iron-doping improved lithium ion adsorption from brines. The saturated adsorption capacity of the iron-doped ion sieves in brine (Li+ 1.56 g/L, pH = 8.8) was 34.8 mg/g. Lithium ion adsorption fitted pseudo-second-order kinetic and Langmuir equations, indicating that lithium ion adsorption on iron-doped lithium ion sieves was chemical and predominantly monolayer. In addition, the iron-doped ion sieves showed excellent selectivity for lithium ion and good recyclability. These iron-doped ion sieves therefore provide effective lithium adsorbents for practical applications.