Inorganic porous carbon as the supporter of H2TiO3 via in-situ polymerization synchronous conversion for lithium recovery from aqueous solutions

Abstract

The extraction of lithium from liquid minerals, such as salt lake brines and underground brines, has garnered extensive interest due to its eco-friendly and cost-effective properties. However, the effectiveness of this method is constrained by the stability and capacity of the materials. Herein, a new-type inorganic carbon-supported H2TiO3 adsorbent was developed by a novel in-situ polymerization synchronous conversion strategy. It was found that when resorcinol and formaldehyde containing Li2CO3 and TiO2 were polymerized in-situ and then calcined at 973.15 K, the resin was successfully carbonized to obtain the carbon supporter with a low degree of disorder, and the Li2CO3 and TiO2 in the supporter were synchronously converted into Li2TiO3 and uniformly dispersed in the carbon matrix. Because of the large specific surface area and strong hydrophilicity of the carbon supporter, the material exhibited a maximum Li+ adsorption capacity of 52.14 mg·g−1, which was far higher than that of inorganic composite materials reported at present. Even the equilibrium adsorption capacity for Li+ at a low concentration of 29.26 mg·L−1 reached 28.51 mg·g−1. Following adsorption, the Li+ in the material was easily eluted by 0.25 mol·L−1 HCl, and the elution rate was more than 90 % within 2 h. Dynamic adsorption using a fixed-bed was also performed at 298.15 and 343.15 K, and the adsorption capacity for the same concentration of Li+ was 7.08 and 9.44 mg·g−1, respectively. Because of the high capacity for low-concentration Li+ and the promoting effect of temperature on adsorption, the material is well-suited for recovering Li+ from liquid resources, particularly from geothermal water with high temperatures and low Li+ concentrations.