High selective adsorption of lithium by photochromic porous SP-C/PVDF membranes with the driven force of an external electric field

Efficient separation of lithium from salt lake brine with a high Mg/Li ratio remains a challenge and the design of functional materials is one of key points determining the selective recovery of lithium. In this work, a photochromic porous SP-C/PVDF membrane was prepared and its selective adsorption properties for Li+ with the driven force of an external electric field were studied. The SP-C embedded in membrane phase still kept stable photochromic activity and the SP-C/PVDF membrane showed sensitive colour-switching under the alternating irradiation of UV/visible light. The hydrophility and porosity of the SP-C/PVDF membranes could be controlled by changing added amount of TiO2 nanoparticles. The SP-C/PVDF membranes exhibited high selective adsorption of Li+ compared with Mg2+ under an external electric field. This work developed a new material and strategy for selective extraction of trace Li+ from aqueous solutions with high Mg/Li ratio, which might be expected to promote the development of lithium extraction from salt lake brines.