Facilitated uranium and organic removal and electricity production via a zinc oxide/carbon felt cathode equipped hybrid tandem photocatalytic fuel cell.

The combined pollution by uranium and organic matter has posed a serious challenge in the treatment of radioactive wastewater, while traditional treatment methods suffered from the problems of poor treatment efficiency and difficult recycling. Therefore, this study developed a novel hybrid tandem photocatalytic fuel cell (HTPFC) system which decorated with a ZnO modified carbon felt (ZnO/CF) cathode. This HTPFC not only efficiently removed UO22+ and organic matter while generating electricity, but can also be quickly disassembled and reassembled. The ZnO loading greatly improved the electrochemical properties of CF and introduced abundant active sites, making the constructed HTPFC exhibited excellent applicability, reusability and practical application prospects. When UO22+ coexisted with various organics, such as p-nitrophenol, ciprofloxacin, atrazine, ibuprofen, sulfamethoxazole, and tetracycline hydrochloride (TCH), the organic matter removal efficiencies were ≥94.36 %, and the UO22+ removal efficiencies were ≥94.56 %, accompanied with a maximum power output density of ≥1.31 mW·cm-2. After five cycles, the UO22+ and TCH removal efficiency still remained 92.34 % and 89.75 %, respectively. Notably, over 98.0 % of each of UO22+ and TCH can be removed under the actual sunlight illumination, indicating that the fabricated HTPFC had a great practical application potential. This study may present a new approach for disposing the complex wastewater containing heavy metals and organic compounds.