Ultra-highly photocatalytic removal of pollutants by polypyrrole/cadmium sulfide/polyether sulfone hybrid porous membrane in single-pass mode

Abstract

A hybrid porous membrane of polypyrrole, cadmium sulfide and polyether sulfone (CdS/[email protected]), which is suitable for dynamic photocatalytic process, has been designed to resolve distressing issues of nanoscale CdS recovery and membrane fouling as well as fast water purification. CdS/[email protected] membrane was fabricated by the deposition of CdS on PES substrate, followed by PPy polymerization. As-prepared CdS/[email protected] membrane was used for the dynamic removal of pollutants (e.g. methylene blue, tetracycline) by a combination of photocatalysis and separation process under visible light illumination. 55%∼82% dynamic pollutants removal can be constantly achieved for hourly single flow (13 ∼ 19 L·m2·h−1, exclusion of interception) in a reaction unit, and such high efficiency is sustainable, which is also confirmed by total organic carbon testing. Furthermore, almost 100% pollutants removal can be fulfilled by 2 or 3 sequential repeated units in flow-through mode. Additionally, the photocorrosion and leakage of CdS were significantly hindered with the protection and promotion of PPy. Compare to conventional cross-flow mode (a large of prefiltered water was pumped out as the concentrated solution and low net output of clean water), all in-put water can be purified in single-pass mode by simple repeated cells. With great and sustainable capacity of photocatalysis degradation and filtration, our membrane becomes a promising candidate for pollutants removal from all income to all clean output.