Electrospun hydrogen manganese oxide nanofibers as effective adsorbents for Li+ recovery from seawater

Highly porous hydrogen manganese oxide (HMO) nanofibers were fabricated by combining electrospinning, calcination, and ion exchanges, and their lithium (Li) recovery performance was systematically compared to other adsorbent types (i.e., nanoparticles and porous microbeads with equivalent properties). In seawater, the HMO nanofibers exhibited an excellent Li+ adsorption capacity (18.8 mg/g) with greater Li+ selectivity over other adsorbents. These might be attributed to the high number of macropores in the nanofiber, which facilitated the inward diffusion of Li+ and enhanced the accessibility of activated sites. Moreover, the Li+ recovery efficiency of the nanofibers remained approximately 95% after 20 recovery cycles.