Enhanced Pulsed Electrocatalytic Removal of Fluorinated Organic Pollutants with Pd Single Atoms and CoP Nanopimples: Synergistic Degradation by Reduction and Oxidation under Air Conditions

Abstract

To efficiently remove the difficult-to-degrade fluorinated organic pollutants in the aqueous environment, Pd1-CoP@NCu electrodes with both reducing and oxidizing bifunctional activities were constructed in this study, and pulsed electrocatalysis was used to achieve their reducing defluorination and oxidizing degradation under air conditions. In the pulsed mode, a periodic enrichment-release process is formed at the electrode interface. The Eon phase mainly drives the H*-mediated C–F bond breaking and generates reactive oxygen species (ROS) through an oxygen reduction reaction, while the Erest phase triggers the water oxidation process through potential reversal, promotes the continuous generation of a variety of ROS, and facilitates the aromatic ring opening and small-molecule mineralization. The system achieved 99.1% degradation, 62.9% defluorination, and 57.5% TOC removal by using pulsed two-phase synergistic action, effectively completing the defluorination, detoxification, and efficient removal of 4-fluorophenol. Therefore, the design of constructing Pd single-atom synergistic sites and introducing pulsed voltage provides new ideas for developing green, efficient, and sustainable electrochemical remediation technologies for fluorinated pollutants.