PVDF/MXene/PI/NH2-UiO-66 composite fiber membranes with Z-scheme heterojunction for visible-light photocatalytic degradation of tetracycline

The indiscriminate of tetracycline (TC) has led to significant environmental and health concerns, particularly the proliferation of antibiotic resistance. This study presents a visible-light photocatalytic composite membrane with a Z-scheme heterojunction to improve TC removal efficiency and address the challenge of catalyst powder recovery in practical applications. Firstly, the PI/NH 2 -UiO-66 (PNs) composite photocatalyst was synthesized via a one-step thermal solvent method. Subsequently, the PVDF/MXene/PI/NH 2 -UiO-66 (PMPNs) composite fiber membrane was successfully fabricated by stably loading the PNs and MXene onto PVDF fiber membranes through electrospinning. Under visible light irradiation, the removal efficiency of TC by the PMPN1.5 composite fiber membrane could reach 86.07% through the combined effects of filtration, adsorption, and photocatalysis. Even after three cycles, the recovery rate of the PMPN1.5 membrane could still reach 86.16%. The enhanced photocatalytic performance was due to the Z-scheme heterojunction between PI and NH 2 -UiO-66. This heterojunction structure enhanced the redox capability of the photocatalyst. Additionally, the incorporation of MXene facilitated effectively charged carrier transfer at the heterojunction interface, prolonging the electron-hole separation time and further improving the photocatalytic capability. This study successfully integrates photocatalytic technology with membrane separation to develop a visible light-responsive composite fiber membrane with considerable potential for treating antibiotic-contaminated wastewater. The developed membrane not only mitigates fouling but is also easily recyclable, minimizing the risk of secondary pollution.