Uranyl adsorption: recent progress of covalent organic framework materials

Covalent organic frameworks (COFs) are crystalline materials that have shown great potential for use within the life science, environmental chemistry, and energy fields owing to their light weight, low density, periodic structure, adjustable pore size, large surface area, and chemical stability. As a naturally occurring radioactive element, uranium is widely used as nuclear fuel, nuclear industry and medicine. It can severely harm the human body during its processing and enrichment. This paper reviews the recent progress of COFs with or without fluorescence sensing or photocatalytic ability for use as uranyl ( UO_2^2 + ) adsorbents, and the interaction mechanisms of COFs with UO_2^2 + are summarized. In addition, the application of UO_2^2 + adsorption in seawater is discussed and the future development trends of UO_2^2 + -based COF materials are prospected.