Interaction Mechanism of U(VI) with Redox Active Covalent Organic Framework: EXAFS Spectroscopy and XPS analysis

Abstract

Treatment of nuclear waste containing low or high level of uranium concentration is one of the critical problems in the radioactive waste management and environmental remediation. Covalent organic frameworks (COFs) are highly promising class of materials for uranium extraction due to high surface area, high stability under harsh environment and tunable structure. In this work, we investigated the interaction of uranium with highly stable redox active covalent organic framework by extended X-ray absorption fine structure spectroscopy (EXAFS) and X-ray photoelectron spectroscopy (XPS). More important, redox active COF has succeeded to reduce uranium concentration in contaminated solution from 1 ppm which 33.3 times higher than Environmental Protection Agency Limit (EPA) for uranium concentration in drinking water to less than 0.09 ppb. The obtained results make our redox active COF a promising adsorbent for uranium decontamination from aqueous solution.