Photocatalytic fuel cell based on highly conductive pathways for norfloxacin removal in mariculture wastewater and simultaneous electricity generation

Antibiotic contamination in mariculture wastewater urgently requires effective remediation. Seawater's natural conductivity facilitates photocatalytic fuel cell (PFC) deployment for meeting this challenge. In this study, the ZnSe/ZnO/Ti core-shell nanorod array photoanode was successfully prepared, which was assembled with carbon cloth (CC) cathode to build the PFC system for norfloxacin (NOR) degradation and simultaneous electricity generation in mariculture wastewater. Experimental results demonstrated that the introduction of the ZnSe shell effectively enhanced the light harvesting capability and formed interfacial electric field at the heterojunction interface, promoting charge transfer performance. The ohmic resistance was the limiting factor for PFC performance enhancement. The Ti plate effectively reduced ohmic resistance, enhanced ion migration rates, and maximized the efficiency of interfacial reactions. The heterojunction, nanorod array, and Ti current collector formed high-conductivity pathways for the rapid directional transport of both charge carriers and electrolyte ions, reducing the resistance of the PFC and significantly enhancing its performance. The PFC system exhibited superior degradation performance with 94.42 % removal of NOR in 120 min. The simultaneous electric energy output of ZnSe/ZnO/Ti-15 was 2.46 mW/cm 2 , which was 2.48 and 2.2 times higher than those of the ZnO/Ti and ZnSe/ZnO/FTO systems, respectively. Moreover, the abundant Cl − in mariculture wastewater acted as supporting electrolyte while also generating Cl•, ClO• radicals, thereby further facilitating degradation. This study provided new insights for the performance improvement of PFC and the resource utilization treatment of marine aquaculture wastewater.