2D MoS₂ nanoplatelets for fouling resistant membrane surface

2D Molybdenum disulfide (MoS₂) nanoplatelets were synthesized via a green bottom-up strategy using non-toxic L-Cysteine as sulfur source. The hydrophobic 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 using bovine serum albumin (BSA) as model 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 MoS₂ coated membrane were underpinned by combined unique interfacial properties offered by 2D tri-atomic layered MoS₂ morphology 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.