pH-responsive laminar WSe2 membrane with photocatalytic antifouling property for ultrafast water transport

Separation membrane with tunable nanochannels displays desirable performance in water treatment. While designing nanogating membranes with superior permeability and antifouling properties still remains a challenge. Here, we report a smart pH-responsive nanogating membrane by assembling two-dimensional polyacrylic acid (PAA) grafted tungsten selenide (WSe2) nanosheets. The nanochannel size of WSe2/PAA membrane varies with the swell or shrink of PAA chains that are regulated by pH, therefore leads to controllable separation capabilities towards mixed molecules solution. The membrane exhibits ultrafast water permeability because of the expanded interlayer space between WSe2 nanosheets and weak interaction between WSe2 and water molecules. Moreover, by virtue of the photocatalytic characteristic of WSe2, the membrane shows enhanced antifouling property. This WSe2/PAA nanogating membrane has great potential applications in nanofluidics system and complex chemical separation.