Harnessing Spatiotemporal Interaction of Redox Reactions Boosts Singlet Oxygen Generation in Electrocatalytic Dual-Membrane Systems

Abstract

Electrocatalytic membrane filtration (EMF) technology presents a transformative approach to efficient emerging contaminant removal by synergistically integrating electrochemical reactions with membrane separation. However, current EMF systems exhibit inadequate control and poor understanding of selective reactive oxygen species (ROS) generation, particularly singlet oxygen (¹O₂), which constrains target-specific degradation capability. Here, we engineered a graphite-felt-based electrocatalytic dual-membrane system to systematically reveal how anode–cathode reactions under spatiotemporal coupling regulate ¹O₂ generation by modulating pH and anode potential. In the optimal configuration (A–C_1), H⁺ and O₂ were produced via oxygen evolution reaction at the upstream anode transport to the downstream cathode interface, creating an acidic environment and continuous oxygen supply conducive to ¹O₂ formation. Compared to the reverse configuration (C–A_1), the A–C_1 configuration enhances the generation of key intermediates (O₂·^– and H₂O₂), significantly boosting the ¹O₂ generation rate (371.9 μmol L^–1min^–1) and achieving improved energy efficiency (17.88 m³ order kWh^–1). This study establishes spatiotemporal-interfacial regulation principles, providing a theoretical foundation for developing highly selective EMF systems.