2D MoS2 nanoplatelets for fouling resistant membrane surface

Abstract

2D Molybdenum disulfide (MoS2) nanoplatelets were synthesized via a green bottom-up strategy using non-toxic l-Cysteine as sulfur source. Thehydrophobic MoS2 nanoplatelets assisted by hydrophilic 3-(3, 4-dihydroxyphenyl)-l-alanine (l-DOPA) were coated on a thin film composite nanofiltration (TFC-NFG) membrane. The accelerated fouling experiments were conducted by usingbovine serum albumin (BSA) asmodel organic foulant,and MoS2 coated membrane demonstrated excellent resistance with almost no flux decline within first hour of filtration, whereas the uncoated membrane showed flux decline immediately from the beginning of the experiment. After 5-hour filtration, the flux reduced by only 26% for MoS2 coated membrane with a higher flux recovery rate of 85.4% after washing by de-ionized (DI) water, whereas 45% flux decline was observed for uncoated membrane with lower flux recovery of 68%.These antifouling effects attributed by MoS2coated membrane were underpinned by combined unique interfacial properties offered by 2D tri-atomic layered MoS2morphology including dispersive surface tension, reduced surface roughness, weaker MoS2-foulant interactive forces, and negatively charged surface. This research positively confirms the role of 2D MoS2 nanoplatelets as an anti-fouling coating on membranes and brings up more possibility for applying other nanomaterials in 2D family in water applications such as desalination and water treatment.