Intralayer Nanoconfined CuO_x Nanocatalysts in Boron Nitride Membrane for Efficient Micropollutant Oxidation

In advanced oxidation processes (AOPs), limited interaction among oxidants, nanocatalysts, and micropollutants severely hinders reaction kinetics and water decontamination efficiency. While nanoconfinement effect enhances reaction kinetics, it remains a challenge to develop a robust nucleophilic interface using low-cost nanocatalysts (e.g., CuO). Herein, a functionalized boron nitride (BN) membrane embedded with CuO_x nanoparticles is developed for ultrafast water treatment. Advanced characterization techniques, including Raman spectroscopy and in situ X-ray photoelectron spectroscopy (XPS), confirm crystallinity, uniform dispersion, and confinement of CuO_x within the BN membrane. According to Density Functional Theory (DFT) simulations, electrophilic and nucleophilic interactions between CuO_x@BN and PMS, with adsorption free energies of up to -3.00 eV, stretched O─O bonds, and thermodynamically favorable reaction pathways, lead to enhanced generation of reactive oxygen species (ROS). Unlike previous studies, the qualitative and quantitative analysis identify ^•OH and ¹O₂ as key reactive species. The CuO_x@BN membrane achieves ultrafast kinetics (60 s^-1) at 160 L m^-2 h^-1 and outperforms control reaction systems. It also demonstrates efficacy for broad-spectrum of micropollutants, high tolerance to changes in water matrix, and efficient redox cycling (Cu⁺ ↔ Cu²⁺) even after 24 h of continuous operation. This work advances nanoconfined catalysis and presents a sustainable, high-performance water treatment technology for efficient water decontamination.