Gravity driven ultrafast removal of organic contaminants across catalytic superwetting membranes

Abstract

Herein, flexible and hierarchical porous catalytic carbon nanofibrous membranes (MnO/Co@SiO₂-CNFMs) driven by gravity were prepared using a co-electrospinning technique and self-reduced pyrolysis. Benefiting from the active metals and precursor carrier design, the composite active MnO/Co crystals can be directly produced without any reducing gases and easily migrate to the carbon nanofiber surface during the carbonization process. Meanwhile, the silica nanoparticles (SiO₂ NPs) doped in the carbon nanofibers (CNFs) can maintain the carbon nanofiber structure without obvious shrinkage as well as transmit and scatter the outer stress, which endowed the membrane with robust flexibility and mechanical strength. The as-prepared MnO/Co@SiO₂-CNFMs exhibited a superhydrophilic surface with a water contact angle of 0°, fast water flux of 752 ± 28 L m⁻² h⁻¹, and prominent catalytic performance with a high degradation efficiency over 99.5% toward methylene blue (MeB). Furthermore, four typical refractory pollutants (phenol, bisphenol-S, chlorophenol and sulfamethoxazole) can also be efficiently degraded by the gravity driven MnO/Co@SiO₂-CNFMs/PMS system. This study is meaningful for the development of novel catalytic membranes with high efficiency and low energy consumption for wastewater treatment.