Boosting U(VI) extraction and existing organic degradation as well as electricity production from wastewater and seawater by a solar-driven multifunctional photocatalytic fuel cell decorated with ZnS/CF cathode.

This work exploited a fresh multifunctional photocatalytic fuel cell (MPFC) technology based on cathode modification for the synchronous elimination of U(VI) and organic contaminant, together with power production. Thanks to the loading of ZnS on a carbon felt (CF) cathode, the removal rates of U(VI) and coexisting organic compound were significantly increased. Under indoor simulated lighting environment, the U(VI) and tetracycline hydrochloride (TCH) elimination rates in this ZnS/CF-MPFC system attained nearly 100%, which were higher than those of CF-MPFC (41.83% and 46.74%). Meanwhile, the ZnS/CF-MPFC exhibited higher power generation than other reported systems. Under actual sunlight exposure outdoor, the ZnS/CF-MPFC system also showed outstanding performance, with U(VI) and TCH elimination rates of 99.63% and 97.60%, separately. When other organic compounds were used instead of TCH, the elimination efficiencies of U(VI) and the coexisting organic compounds exceeded 81% and 92%, respectively. In the simulated actual seawater, the elimination rates of uranyl carbonate and organic matter were approximately 100%. These experiments indicated that the constructed MPFC had strong adaptability and practical application prospects, could effectively eliminate U(VI) and organic contaminant, and generate green energy synchronously in various water environments.