In-situ incorporation of halloysite nanotubes with 2D zeolitic imidazolate framework-L based membrane for dye/salt separation

Abstract

Layered assembled membranes of 2D leaf-like zeolitic imidazolate frameworks (ZIF-L) nanosheets have received great attention in the field of water treatment due to the porous structure and excellent antibacterial ability, but the dense accumulation on the membrane surface and the low permeate flux greatly hinder their application. Herein, we synthesized mHNTs (modified halloysite nanotubes)/ZIF-L nanocomposites on modified mHNTs by in situ growth method. Interestingly, due to the different size of mHNTs and ZIF-L, mHNTs were packed in ZIF-L nanosheets. The hollow mHNTs provided additional transport channels for water molecules, and the accumulation of the ZIF-L nanosheets was decreased after assembling mHNTs/ZIF-L nanocomposites into membrane by filtration. The prepared mHNTs/ZIF-L membrane presented high permeate flux (59.6 L·m−2·h−1), which is 2–4 times of the ZIF-L membranes (14.8 L·m−2·h−1). Moreover, mHNTs/ZIF-L membranes are intrinsically antimicrobial, which exhibit extremely high bacterial resistance. We provide a controllable strategy to improve 2D ZIF-L assembles, and develops novel membranes using 2D package structure as building units.