Fabrication of N,C-H2TiO3 ion sieves for rapid adsorption of lithium using rheological phase methods

Modifying β-H2TiO3 by elemental doping improves its adsorption capacity and shortens the equilibrium adsorption time, which is of positive significance for its industrial application. Herein, a novel N, C co-doped Li2TiO3 lithium ion sieve precursor N,C-Li2TiO3-3 (noted as N,C-LTO-3) was successfully prepared via the rheological phase method using urea as a vital raw material. Crystal structure of N,C-LTO-3 was characterized via XRD, XPS, FT-IR, and Raman. The morphology of N,C-LTO-3 was analysed by SEM and HR-TEM. The N,C-LTO-3 was pickled and obtained to N,C-H2TiO3-3, namely N,C-HTO-3. The equilibrium adsorption capacity (Qe) of N,C-HTO-3 was as high as 40.6 mg⋅g−1 in LiOH solution of 100 mg·L−1 at 293 K. Ti4+ dissolution loss rate is below 0.5 % in the fifth cycle. Adsorption isothermal curve, kinetics, and thermodynamic behaviour were fitted with the according equations. The exchange energy of N,C-HTO-3 for Li+ was calculated by density functional theory (DFT) to assess the feasibility of lithium absorption. Furthermore, N,C-HTO-3 exhibited high regeneration and selectivity for Li+ in lithium-containing brine, making N,C-HTO-3 an ideal candidate for Li+ extraction. [Display omitted] •N,C-HTO-3 were synthesized via rheological phase method using urea as fuels.•N,C doping changed the stacking fault concentrations of Li2TiO3.•The exchange energy after N,C doping was calculated using DFT