Photoinduced superwetting membranes for separation of oil-in-water emulsions

The separation of oil/water emulsion has become a pressing worldwide problem. In this study, a novel type of photoinduced separation membrane was prepared via layer-by-layer (LBL) method of ZIF-8/GO composite. By integrating the unique physical and chemical properties of ZIF-8 and GO, the ZIF-8/GO membrane exhibits superior superoleophobicity under visible light and underwater anti-fouling for efficient oil rejection from water. We found that the ZIF-8/GO membrane permeation flux was 110 +/- 6 L m(-2) h(-1) under light irradiation, which was higher than the permeation flux of membranes without irradiation (50 +/- 6 L m(-2) h(-1)). For toluene, the removal rate was about 100% at the first time, with new benzyl alcohol and benzaldehyde products detected in the filtrate, indicating that toluene was degraded on the ZIF-8/GO membrane surface. Continuous separation performed using filtration apparatus demonstrates a high separation capacity, with long-term membrane stability. The high water flux, high separation capacity and capacity for large-scale preparation of the ZIF-8/GO membrane, shows great potential for industrial application in the treatment of oil-containing wastewater.