Thin-film nanocomposite membranes containing tannic acid-Fe3+ modified MoS2 nanosheets with enhanced nanofiltration performance

Abstract

The development of thin-film nanocomposite (TFN) membranes for water treatment is of immense scientific interest. In this work, MoS2 nanosheets modified with tannic acid (TA)-Fe3+ coordination complexes were embedded within the polyamide (PA) layer to construct TFN nanofiltration (NF) membranes. The incorporation of modified MoS2 nanosheets into the PA matrix facilitates the formation of a bumpy surface with the appearance of scattered protuberances. Besides, the introduced covalent bonding between phenol groups and unreacted acid chloride groups during interfacial polymerization contributes to an enhanced crosslinking degree of the PA layer, simultaneously avoiding the formation of non-selective interfacial voids. The optimal TFN NF membrane with the addition of 0.01 wt% modified MoS2 nanosheets demonstrates 1.6-fold water permeance of the TFC membrane, along with increased salt rejection. The improved permeance of the TFN membrane is mainly due to the crumpled surface architecture with high roughness, which increases the permeable area for water transport. Overall, our study suggests that the employment of TA-MoS2 nanosheets for the construction of TFN membranes can be a promising method to develop high-performance NF membranes.