Highly Efficient Oxygen-Activated Self-Cleaning Membranes Prepared by Grafting a Metal–Organic Framework-Derived Catalyst

In this study, an efficient oxygen-activated
self-cleaning membrane
was successfully prepared by grafting a metal–organic framework-devised
catalyst (CuNi–C) onto a membrane surface, resulting in enhanced
filtration performance and self-cleaning capability based on oxygen
activation under mild conditions. The pore features, surface roughness,
and surface hydrophilicity of the prepared membrane were analyzed
and used to determine the causes of the enhanced filtration performance;
the results showed that an increase in the porosity and surface roughness
enhanced the permeate flux, and enhanced adsorption capacity and surface
hydrophobicity improved the membrane removal efficiency. The self-cleaning
mechanism was elucidated by identifying the reactive oxygen species
(ROS) and detecting catalytic element valences. The results revealed
that zero-valent Cu embedded into the membrane surface effectively
activated natural dissolved oxygen (DO) to generate ROS that degraded
organic pollutants. In this study, catalytic oxidation with DO as
the oxidant was successively integrated with membrane separation to
prevent membrane fouling, providing a novel direction for the development
of multifunctional membranes.