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

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.

Automated summary

In this study, Ti/BiOI-pDA/CA photocatalytic nanocomposite membranes were successfully developed for efficient removal of tetracycline (TC). These membranes exhibited high photocatalytic activity and excellent antifouling performance, showing great potential for practical wastewater treatment in the future.