Solar light-responsive CdS/UiO-66-NH2 for ultrafast uranium reduction from uranium-containing mine wastewater without external sacrificial agents

As the nuclear industry ushered in a historical opportunity for rapid development, the massive discharge of nuclear waste liquids posed health risks to humans and environmental pollutant due to its combined chemotoxicity and radiotoxicity. Therefore, how to effectively treat uranium-containing mine wastewater is full of challenges. In this work, the CdS/UiO-66-NH2 nanoparticles photocatalysts were prepared and applied for reduction of uranium hexavalent in the absence of any sacrificial agents. The kinetic photoreaction rate reaches 3.78 mmol/(g·h), which is a record among the reported rate. Excitingly, 85.62% of U(VI) in the mine wastewater could be removed under sunlight irradiation in the air condition. The results show that the photogenerated electrons rapidly transport from CdS to UiO-66-NH2 due to the formation of heterojunction structure, whereas the photo-generated holes are consumed by oxidizing S2− to SO42−. This work represents an important step towards the remediation of the radioactive environment from mine wastewater, and promotes the extensive application of photocatalysis technology.