Integrating advanced Keggin-structure polyoxometalate into polymeric membrane to enhance photocatalytic self-cleaning and antifouling functionalities

The high photocatalytic activity of environmentally benign Keggin-type polyoxometalate (POM) was introduced into polyethersulfone (PES) membrane to promote membrane anti-fouling and self-cleaning functionality. Neat PES and POM/PES hybrid membranes were synthesized via phase inversion method. X-ray diffraction (XRD) and attenuated total reflection-Fourier transform infrared (ATR-FTIR) spectroscopy proved the success of synthesizing Keggin-type POM. The traits of the membranes were evaluated using scanning electron microscopy (SEM), ATR-FTIR, contact angle measurement, porosity and porometer. The hydrophilicity of all the POM/PES hybrid membranes was enhanced and resulted in the reduction of contact angle of the membrane (52.21±0.1101°, 45.11±0.6657° and 50.30±0.1054°) for 0.025, 0.05 and 0.1 wt% POM/PES hybrid membranes, respectively, compared to that of the neat PES membrane (57.30±0.0817°). Additionally, all the POM/PES hybrid membranes showed excellent anti-fouling and self-cleaning characteristics as compared to that of the neat PES membrane. 0.05 wt% POM/PES hybrid membrane outstood all the other membranes, which marks the HA rejection at 77.12% and was able to achieve flux recovery ratio (FRR) of 111.34% with temporal superhydrophilicity effect in just merely 150 seconds at 254 nm UV irradiation.