Nature-mimicking fabrication of antifouling photocatalytic membrane based on Ti/BiOI and polydopamine for synergistically enhanced photocatalytic degradation of tetracycline

Abstract

The photocatalytic efficiency of conventional blending photocatalytic membranes suffers a significant reduction due to effective photocatalyst embedded in membrane matrix. Therefore, in this study, inspired by the bioadhesive technology of polydopamine (pDA), a novel Ti doped bismuth oxyiodide (BiOI)-polydopamine (pDA)-coated cellulose acetate (CA) (Ti/BiOI-pDA/CA) photocatalytic nanocomposite membranes were successfully developed for effective removal of tetracycline (TC). The Ti/BiOI-pDA/CA nanocomposite membranes displayed very high photocatalytic activity toward TC (about 98% after 120 min) under visible light irradiation and superior photodegradation kinetics (k=0.03214 min−1). The removal rate of Ti/BiOI/-pDA/CA nanocomposite membranes under dynamic cyclic degradation system could be further improved, giving TC removal efficiency of 91% in 60min. Remarkably, the permeate flux, flux recovery ratio (FRR), reversible fouling (Rr), irreversible fouling (Rir) and the total fouling ratio (Rt) revealed the Ti/BiOI-pDA/CA nanocomposite membranes had excellent antifouling performance. In addition, the Ti/BiOI-pDA/CA nanocomposite membranes exhibited excellent stability and reusability. Therefore, this work gives insight into the effective removal of TC wastewater and has a great potential for new generation of high-performance photocatalytic membranes for practical wastewater treatment in the future.