Highly efficient antibacterial adsorbent for recovering uranium from seawater based on molecular structure design of PCN-222 post-engineering

Herein, a novel amidoxime functionalized metal organic framework (MOF)-based adsorbent named PCN-222-AO was obtained by grafting amidoxime groups on the surface of PCN-222 through amination, cyanylation and amidoximation modification reactions successively. The PCN-222-AO exhibited outstanding adsorption capacity (432.7 mg·g−1), selectivity and reusability in U(VI) adsorption at pH = 7.0, and showed superb adsorption performances in the simulated and real seawater. The XPS spectra and adsorption energy calculations confirmed the CN (H2TCPP), C=N-OH and -NH(2) groups served a vital role in the U(VI) adsorption process. PCN-222-AO illustrated excellent antibacterial property, anti-biofouling activity and environmental safety, which effectively reduced the negative impacts of bacteria (E. coli and S. aureus) and Halamphora upon the U(VI) adsorption capacity and complied with the requirements for non-toxicity and innocuousness in the adsorbent application. The excellent antibacterial property and anti-biofouling activity may be attributed to Zr6 cluster and abundant functional groups in the PCN-222-AO. Undoubtedly, the molecular structure design and construction of effective adsorbents are crucial for the U(VI) resource recovery. As first reported in this study, PCN-222-AO is a promising adsorbent to recover U(VI) from seawater, providing a new idea about the molecular structure design and construction of novel high-efficiency adsorbent.