Anchoring multi-mechanism coupled miniature redox reactors with photothermal foam gels for simultaneous photoreduction U(VI) and interfacial evaporation from wastewater

Photocatalytic technology emerges as a potential option for treating uranium-containing wastewater. However, the single energy conversion pathway from solar to chemical energy still suffers from low solar utilization. Herein, we developed a “self-floating” dual-network photothermal foam gel (SGC@Cu₂₊₁O/Cu_1,0.1) using a physical foaming-sol-gel method. An adsorption-photothermal catalysis triple coupling system was developed to achieve dual-path energy conversion from solar energy to chemical and thermal energy. Cu₂₊₁O/Cu photocatalysts anchored in foam gels exhibited faster charge transfer and segregation, and wider light absorption range due to the construction of vacancy defects and Schottky potential wells as well as the introduction of plasma Cu particles. As a result, SGC@Cu₂₊₁O/Cu_1,0.1 achieved over 99 % uranium removal within 40 min, demonstrating excellent selectivity and reproducibility for U(VI). Remarkably, a synchronous reaction pathway for solar-driven photoreduction of U(VI) and clean water production was proposed. SGC@Cu₂₊₁O/Cu_1,0.1 achieved 98.3 % removal of U(VI) from lake water, with an evaporation rate of 1.89 kg/m²/h, surpassing that of most solar evaporators. The development and application of SGC@Cu₂₊₁O/Cu_1,0.1 foam gels offer innovative solutions and theoretical insights for the high-value utilization and conversion of uranium-containing wastewater.