Accordion-like Co3O4@MXene nanoreactor with nanoconfined augmentation in membrane for enhanced water purification

Nanostructured multifunctional membranes, integrating filtration and catalytic degradation, show significant potential for wastewater purification with lower energy consumption and carbon footprints in favor of the Sustainable Development Goals (SDGs). However, conventional catalytic membranes face challenges like slow mass transfer and insufficient reactive oxygen species (ROS) production. Hence, we developed accordion-like Co 3 O 4 @MXene nanoreactors as membrane building blocks. These nanoreactors create enormous nanoconfined spaces that augment the efficiency of catalytic oxidation reactions. This design optimizes both filtration and catalytic performance, enabling the removal of small molecule organic pollutants that conventional microfiltration membranes cannot achieve. Experimental results demonstrated over 95% bisphenol A (BPA) removal within 10 minutes by peroxymonosulfate (PMS). The confined membrane can stably maintain approximately 100% BPA removal at a high flux of 770.4 ∙L∙m -2 ∙h −1 for over 120 hours’ continuous operation. Low cobalt leaching (5.35 μg/L) was detected following prolonged operation, validating the system's durability and safety. Theoretical modeling and simulations confirmed the contributions of nanoconfined space in terms of thermodynamics and fluid behavior. Serving as an example of confinement engineering in membranes, this study reveals the immense potential of applying confined nanoreactors for water purification, achieving both high pollutant removal efficiency and water permeability. • Accordion-like Co 3 O 4 @MXene nanoreactors were designed and assembled into catalytic confined membranes. • Confined nanochannels within the nanoreactor enhanced PMS activation and pollutant degradation. • Membrane demonstrated high-efficiency organic pollutant removal at a high flux of 770.4 L·m -2 ·h -1 over 120 hours of continuous operation. • Theoretical calculations and finite element simulations elucidated the mechanisms of mass transfer and nanoconfined catalysis.