One-step phosphidation-prepared FeP@ECC achieves efficient H2O2 generation and activation in the electro-Fenton system for the degradation of sulfamethoxazole: Enhanced active sites and electron transfer efficiency

Simultaneously efficient H2O2 production and activation at the same active site remains a challenge for heterogeneous electro-Fenton (hetero-EF). Herein, the composite cathode consisting of FeP loaded on etched carbon cloth (FeP@ECC) was fabricated by a one-step low-temperature phosphorization strategy. The study shows that the significant enhancement of carbon defects and oxygen-containing functional groups in ECC leads to its excellent H2O2 yield (488.53 mu mol/L). Moreover, the constructed surface FeP structure not only exposes more active sites inside the ECC electrode but also significantly enhances electron transfer efficiency due to the electron-donating characteristics of phosphorus (P), enables rapid activation of H2O2 to produce abundant reactive oxygen species (ROS), achieving complete sulfamethoxazole (SMZ) degradation within 20 min. Significantly, FeP@ECC electrode possesses great stability, universality and actual wastewater application potential. Based on DFT calculation and toxicity assessment, the deeply relevant relationship between ROS attack sites and degradation pathways and the toxicity changes of degradation products are revealed. Overall, this work provides a novel vision for the development of efficient difunctional cathode for wastewater reuse.