Two-dimensional molybdenum disulfide oxide (O-MoS2) enhanced tight ultrafiltration membrane with improved molecular separation performance and antifouling properties

Abstract

Tight ultrafiltration (TUF) membranes have shown potential for separating small molecules such as dyes and natural organic matters. However, low permeability and membrane fouling are critical challenges for TUF membranes. In this study, we reported a feasible method to fabricate a TUF membrane by blending polyethersulfone (PES) with novel two-dimensional (2D) molybdenum disulfide oxide (O-MoS2) nanosheets via the phase inversion method. The results indicated that the O-MoS2 could tune the properties and morphologies of TUF membranes. It was found that the addition of 2.0 wt% of O-MoS2 into the PES membrane could reduce the molecular weight cut-off (MWCO) of the O-MoS2/PES membrane from 15322 Da to 8404 Da. As a result, the optimized O-MoS2/PES membrane showed excellent rejections to PEG 10 kDa (92.67 ± 0.12%) and Rose bengal (99.9%). Moreover, The optimized O-MoS2/PES membrane exhibited a high pure water flux (75.24 ± 4.29 L m−2h−1bar-1). By using bovine serum albumin (BSA) as the simulated foulants, the antifouling performance of as-prepared membranes was investigated. The result indicated that the optimized O-MoS2/PES membrane had 88.15% water recovery rate after a 420-min continuous filtration test, which was higher than 80.53% of the pristine membrane. This study demonstrated O-MoS2 could be used as a novel additive to prepare a TUF membrane with high filtration performance.