Ag@SnS/PVDF membranes with self-cleaning ability driven by photocatalysis process

Abstract

Coupling photocatalysis with membrane separation technology becomes one pioneering method to solve the membrane fouling. In this study, Ag@SnS photocatalyst was synthesized and blended with polyvinylidene fluoride (PVDF) to fabricate Ag@SnS/PVDF composite membranes via non-solvent induce phase separation (NIPS) method. The results show that with the addition of Ag@SnS, water flux of Ag@SnS/PVDF hybrid membranes increases due to the enhanced membrane hydrophilicity and increased porosity. The optimal hybrid membrane (MAS-2) exhibits the rejection rate of 97.0 % and 95.4 % for BSA and HA accompanied with a water permeance of 578.5 L m⁻² h⁻¹ bar⁻¹. Moreover, MAS-2 membrane reveals excellent self-cleaning ability by photodegradation of HA on membrane surface, and its flux recovery rate (FRR) can achieve 91.7 % after UV irradiation and 95.8 % after 3 h natural sunlight irradiation via photocatalysis regeneration. The heterostructure of Ag@SnS can assist separation of photoinduced electrons and holes by transferring photoinduced electrons to Ag nanoparticles with enhanced photocatalytic activity. After three cycles, the FRR can still reach around 90.0 %, revealing its outstanding cleaning ability. Therefore, the Ag@SnS/PVDF membranes have a foreseeable potential in the field of water treatment due to its high flux performance, self-cleaning ability via photocatalysis process.