Electrocatalytic membranes with spatially confined 3D graphene hydrogel–supported copper nanoparticles for advanced water remediation

An electrocatalytic Cu-GHM system with tunable nanoconfined spaces is constructed. • The electrified system enables 73%–100% degradation of 13 emerging contaminants. • 100 h of continuous operation is demonstrated without loss of structural integrity. • The electrified system also exhibits high energy efficiency (0.07 kWh/m 3 ). • DFT calculations and MD simulations elucidate the degradation mechanism. Persulfate-based advanced oxidation processes are promising for removing refractory contaminants from aquatic systems, however, their performance is often constrained by limited reactive oxygen species utilization and restricted mass transfer. Although spatial confinement engineering of electrocatalytic membranes has improved persulfate activation, the underlying structure–property–performance relationships remain insufficiently understood. Here, we report an electrochemical peroxomonosulfate activation system employing a three-dimensional graphene hydrogel-supported copper nanoparticle membrane (Cu-GHM) as the cathode. The system demonstrated broad applicability, achieving 73%–100% degradation across 13 representative emerging contaminants in real water matrices. Its long-term stability was further confirmed through a 100-h continuous operation test specifically using ranitidine as the model pollutant. By regulating pore architecture through controlled compression, the nanoconfined space was tuned from 13.5 to 5.0 nm, revealing a strong dependence of catalytic performance on confinement scale. The smallest pore size (5.0 nm) resulted in an 8.1-fold enhancement in degradation kinetics, attributed to increased local reactant concentration, improved mass transport, and facilitated interfacial electron transfer. Comprehensive spectroscopic analyses and molecular dynamics simulations elucidated the confinement-enhanced catalytic pathways and mass-transfer behavior. This study provides mechanistic insights into synergistic nanoconfinement and electric-field effects, offering a rational framework for designing energy-efficient electrified membrane systems for water treatment. Download: Download high-res image (250KB) Download: Download full-size image