Photocatalytic and Electrocatalytic Extraction of Uranium by COFs: A Review

The highly selective and effective enrichment of U-(VI) from seawater and nuclear industry wastewater is important not only for nuclear power development and dependable energy source, but also for reducing the potential threat of radionuclides to the environment and human health. Covalent organic frameworks (COFs) are ideal materials for trapping U-(VI) ions in aqueous solutions because of their advantages such as inherent porosity, strong skeleton, chemical stability, and good structural regularity. Herein, the most recent developments in the investigation of COFs for efficient preconcentration and separation of U-(VI) by adsorption, photocatalysis, and electrocatalysis from seawater and radioactive wastewater are reviewed. The performance and related mechanisms of U-(VI) interaction with COFs are carefully analyzed from the results of batch sorption experiments, the advanced spectroscopy analysis, and theoretical calculations. The potential and challenges of the present regarding the use of functional COFs for U-(VI) extraction are described. Our aim is to provide insight and advice for the creation of innovative functional COFs for U-(VI) extraction with high efficiency and selectivity in the future.