Metal-free heterogeneous electro-Fenton with solid polymer electrolytes: A novel self-supporting system for PPCPs decontamination

To overcome the limitations of traditional Electro-Fenton (EF) in natural waters, such as low conductivity and metal ion leaching, we developed a novel metal-free EF system incorporating solid polymer electrolytes (EF-SPE). Nitrogen-doped carbon cathodes, optimized via calcination (e.g., 800 °C), enabled efficient in-situ H 2 O 2 electro-generation and activation for carbamazepine (CBZ) degradation. This EF-SPE system achieved a CBZ degradation half-life of 10 min (k = 0.052 min −1 ), operated effectively across a broad pH range (3–9), and exhibited low specific energy consumption for mineralization (6.73 kWh·m −3 ). Experimental and computational studies reveal that graphitic N and pyridinic N were the primary active sites for the electro-generation of H 2 O 2 and its activation to •OH, respectively. The system demonstrated universal efficacy for various pharmaceuticals and personal care products in different natural waters, showcasing its potential for sustainable water purification.