MOFs derived 3D sea urchin-like carbon frameworks loaded on PVDF membranes as PMS activator for highly efficient bisphenol A degradation

Catalytic membrane integrated with advanced oxidation processes (AOPs) was provided a promising prospect to overcome the obstacles of powder catalyst large-scale practical applications. Herein, we utilized a facile strategy to construct novel 3D sea urchin-like nitrogen doped carbon nanotube (CNT) frameworks encapsulated Co nanoparticles (ZIF-67/CNTs) through N-molecule assisted pyrolysis of ZIF-67, and then immobilized on poly(vinylidene fluoride) (PVDF) membrane to obtain the catalytic membranes (ZIF-67/CNTs-II@PVDF). As expected, benefiting from the strongly synergistic effect of high N-doping level, encapsulated 0D Co NPs, 1D N-CNTs and abundant Co@Co-N_x/pyridinic-N active sites and 3D porous structures, ZIF-67/CNTs-II achieved the best catalytic activity towards degrading bisphenol A (96.8%, 40 min and 0.0956 min⁻¹), which was over 3 times higher than that of ZIF-67-derived ZIF-67/Cs (67.8%, 40 min and 0.0306 min⁻¹). Furthermore, ZIF-67/CNTs-II@PVDF catalytic membrane not only exhibited the excellent catalytic ability in different pollutants/PMS system, but also maintained the desirable reusability and stability even after five runs. Notably, ZIF-67/CNTs-II as pore forming centers promoted the active sites exposure for oxidants and target pollutants. Scavenger experiments and EPR analysis verified that SO₄^[rad]−, ^[rad]OH and ¹O₂ participated the degradation process, while SO₄^[rad]− was the major active species. More significantly, this work provides a feasible pathway to fabricate novel catalytic membrane for environmental remediation.