摘要：SummaryIn this work, a spinel single-crystalline Li1.1Mn1.9O4has been successfully synthesized using β-MnO2nanotubes as the self-sacrifice template. The tubular morphology was retained through solid-state reactions, attributed to a minimal structural reorganization from tetragonal β-MnO2to spinel Li1.1Mn1.9O4. The materials were investigated as sorbents for lithium recovery from LiCl solutions, recycled using H2SO4and (NH4)2S2O8. Li1.1Mn1.9O4nanotubes exhibited favorable lithium extraction behavior due to tubular nanostructure, single-crystalline nature, and high crystallinity. (NH4)2S2O8eluent ensures the structural stability of Li1.1Mn1.9O4nanotube, registering a Li+adsorption capacity of 39.21 mg g−1(∼89.73% of the theoretical capacity) with only 0.08% manganese dissolution after eight adsorption/desorption cycles, compared to that of 1.21% for H2SO4. It reveals the degradation of sorbent involves with the volume change, Mn reduction, and Li/Mn ratio depletion. New strategies, based on nanotube adsorbent and (NH4)2S2O8eluent, can extract lithium ions at satisfactorily high degrees while effectively minimizing manganese dissolution.Graphical AbstractDisplay OmittedHighlights•Single-crystalline Li1.1Mn1.9O4nanotubes were developed for lithium extraction•The sorbent showed Li/Mn ratio depletion over adsorption/desorption processes•Acid-free extraction minimized the structural change and Mn reduction•Acid-free extraction improved the chemical stability and reusability of the sorbentChemical Engineering; Materials Science; Materials Chemistry
