Preparation of a modified PATFC membrane coated with a novel visible light response catalyst and its anti-pollution properties
In this study,AgI,graphene oxide(GO)and ultra-thin g-C3N4(UCN)were used as precursors,a type of visible light responsive AgI@GO@UCN(AGU)photocatalyst was synthesized through ultrasonic and chemical precipitation.Then,nitrogen press filtration combined with interfacial polymerization was used to load AGU on the surface of supporting polyamide membrane(PATFC),and AGU modified PATFC membrane was obtained.The preparation process conditions and anti-pollution properties of the modified membrane were studied.The results showed that the optimum preparation conditions were as follows:AGU dosage of 30 mg,MPD aqueous solution mass fraction of 1.0‰,MPD soaking time of 2 min,TMC organic phase solution mass fraction of 0.25‰,TMC soaking time of 45 s;Under the optimal preparation conditions,the pure water flux was 21.84 L·(m2·h)-1(suction pressure 0.2 MPa),and the retention rate of Congo red(CR)could reach 97.80%.The hydrophilicity was significantly improved,and the water contact angle decreased from 57.1°(PATFC)to 40.7°(AGU).The visible light absorption performance of the modified film increased significantly,and the red shift of its maximum absorption side band occurred from 387 nm to 488 nm.The modified membrane had a good anti-pollution performance,and its specific flux increased to 92.75%from 69.54%of PATFC membrane.The modified film had good photocatalytic self-cleaning properties,and the flux recovery rate could reach 95.83%after 60 min illumination.The modified film had a high stability,and its flux recovery rate could reach 92.35%and CR retention rate was still 97.29%after recycling for 6 times.