Carbon dots and polyurethane composite for photo-induced elimination of uranium under air atmosphere

Uranium is the main fuel of nuclear power and elimination uranium from nuclear wastewater is significant both in environmental protection and fuel recycle. Here we report for the first time the synthesis of carbon dots/polyurethane (CDs/PU) composite materials for the photoinduced elimination of uranium from water. Irradiated with visible light, CDs/PU could eliminate uranium efficiently with the generation of (UO2)O2‧2H2O as solid products in air. The further investigated mechanism showed that the addition of CDs/PU could produce more H2O2 under visible light, which reacted with uranyl ions to form (UO2)O2‧2H2O. Importantly, the sponge-like CDs/PU could be easily removed from water with high reusability as the elimination efficiency remained above 95% after 5 cycles. CDs/PU also displayed good selectivity in the presence of other metal ions. Our work affords exciting strategies for developing photocatalysts and eliminating uranium from water.