TY - JOUR
T1 - Lithium ion-selective membrane with 2D subnanometer channels
AU - Razmjou, Amir
AU - Eshaghi, Ghazaleh
AU - Orooji, Yasin
AU - Hosseini, Ehsan
AU - Korayem, Asghar Habibnejad
AU - Mohagheghian, Fereshteh
AU - Boroumand, Yasaman
AU - Noorbakhsh, Abdollah
AU - Asadnia, Mohsen
AU - Chen, Vicki
PY - 2019/8/1
Y1 - 2019/8/1
N2 - In the last two years, the rapidly rising demand for lithium has exceeded supply, resulting in a sharp increase in the price of the metal. Conventional electric driven membrane processes can separate Li+ from divalent cations, but there is virtually no commercial membrane that can efficiently and selectively extract Li+ from a solution containing chemically similar ions such as Na+ and K+ . Here, we show that the different movement behavior of Li+ ion within the sub-nanometre channel leads to Li+ ion-selectivity and high transport rate. Using inexpensive negatively charged 2D subnanometer hydrous phyllosilicate channels with interlayer space of 0.43 nm in a membrane-like morphology, we observed that for an interlayer spacing of below 1 nm, Li+ ions move along the length of the channel by jumping between its two walls. However, for above 1 nm spacing, the ions used only one channel wall to jump and travel. Molecular dynamic (MD) simulation also revealed that ions within the nanochannel exhibit acceleration-deceleration behavior. Experimental results showed that the nanochannels could selectively transport monovalent ions of Li+> Na+> and K+ while excluding other ions such as Cl− and Ca2+ , with the selectivity ratios of 1.26, 1.59 and 1.36 for Li+/Na+ , Li+/K+, and Na+/K+ respectively, which far exceed the mobility ratios in traditional porous ion exchange membranes. The findings of this work provide researchers with not only a new understanding of ions movement behavior within subnanometer confined areas but also make a platform for the future design of ion-selective membranes.
AB - In the last two years, the rapidly rising demand for lithium has exceeded supply, resulting in a sharp increase in the price of the metal. Conventional electric driven membrane processes can separate Li+ from divalent cations, but there is virtually no commercial membrane that can efficiently and selectively extract Li+ from a solution containing chemically similar ions such as Na+ and K+ . Here, we show that the different movement behavior of Li+ ion within the sub-nanometre channel leads to Li+ ion-selectivity and high transport rate. Using inexpensive negatively charged 2D subnanometer hydrous phyllosilicate channels with interlayer space of 0.43 nm in a membrane-like morphology, we observed that for an interlayer spacing of below 1 nm, Li+ ions move along the length of the channel by jumping between its two walls. However, for above 1 nm spacing, the ions used only one channel wall to jump and travel. Molecular dynamic (MD) simulation also revealed that ions within the nanochannel exhibit acceleration-deceleration behavior. Experimental results showed that the nanochannels could selectively transport monovalent ions of Li+> Na+> and K+ while excluding other ions such as Cl− and Ca2+ , with the selectivity ratios of 1.26, 1.59 and 1.36 for Li+/Na+ , Li+/K+, and Na+/K+ respectively, which far exceed the mobility ratios in traditional porous ion exchange membranes. The findings of this work provide researchers with not only a new understanding of ions movement behavior within subnanometer confined areas but also make a platform for the future design of ion-selective membranes.
KW - Subnanometer channels
KW - Li ion selective membrane
KW - Two-dimensional materials
KW - Lithium extraction
KW - Vermiculite
UR - http://www.scopus.com/inward/record.url?scp=85065627726&partnerID=8YFLogxK
U2 - 10.1016/j.watres.2019.05.018
DO - 10.1016/j.watres.2019.05.018
M3 - Article
C2 - 31102860
AN - SCOPUS:85065627726
SN - 0043-1354
VL - 159
SP - 313
EP - 323
JO - Water Research
JF - Water Research
ER -