CNTs/TiO2- loaded carbonized nanofibrous membrane with two-type self-cleaning performance for high efficiency oily wastewater remediation

Fouling of polymeric membranes for oily wastewater has been a major challenge because of the imperfection of regeneration methods. Herein, we designed and fabricated an anti-fouling polyacrylonitrile (CPEN) membrane by assembling the CNTs-COOH and TiO2 via ultrasound, self-assembly, and calcination methods. The bonding structured carbonized membrane demonstrated splendid selective wettability for various oil and water, robust mechanical property (stress load ≈ 7.8 MPa), outstanding thermal stability (400 ℃), and remarkable resistance for acid (1 M HCl)/alkali (1 M NaOH)/salt (3.5% wt NaCl)/solvent (DMF). As a result, relying on the CNTs/TiO2 layer, the surfactant-free and surfactant-stabilized oil-in-water emulsions can achieve an efficient separation (flux can reach 1180 – 3160 L m −2 h−1, R > 99%). Moreover, under photo radiation, the CPEN-CNTs/TiO2 membrane also possessed antifouling and self-cleaning performance, and achieved continuous purification of the dyes/oil emulsions (Roil > 99%, Rdye > 97%). Importantly, under the pyrolysis-induced self-cleaning method, facing the high adhesion crude oil emulsions, the CPEN-CNTs/TiO2 membrane achieved efficient purification and full recovery of the membrane (Rir ≈1.1%). We believe that the presented strategy on two-type self-cleaning membrane fabrication has broad prospects in the multifunctional oily wastewater remediation and revivable membrane.