Resourceful treatment of complex uranium-organic wastewater by a hybrid tandem photocatalytic fuel cell with SnS2 nanoplate modified carbon felt cathode

Resourceful treatment of wastewater is a promising way to facilitate sustainable development. Recently, photocatalytic fuel cells (PFCs) have attracted widespread attention as the method that can synchronously achieve wastewater treatment and clean energy production only depend on light. However, few PFCs focused on treating complex uranium (U(VI))-organic wastewater. This study prepared a SnS₂ nanoplate decorated carbon felt (SnS₂/CF) material by facile hydrothermal method and used as the cathode to construct a hybrid tandem photocatalytic fuel cell (HTPFC) system. Compared to the CF-HTPFC, the removal efficiencies of U(VI) and tetracycline hydrochloride (TCH) increased to 3.4 and 1.8 times in the SnS₂/CF-HTPFC system, accompanied with the reaction rate (k_obs) values increased to 30.39 and 3.78 times, respectively. More importantly, under real sunlight irradiation (From 10:00 to 16:00), the removal efficiencies of U(VI) and TCH respectively reached 92.49 % and 97.96 %, and the P_max reached 6.49 mW·cm⁻². HTPFC also displayed satisfactory performances in treating radioactive wastewater containing different organic compounds, with the removal efficiencies of U(VI) and organic compounds both exceeded 93.35 %. The loading of SnS₂ nanoplates enhanced electrochemical performance and introduced abundant S active sites, allowing more U(VI) to be adsorbed and reduced, and simultaneously promoting the removal of organic matter by improving the charge separation efficiency.