Constructing a crosslinked architecture in conjugated microporous polymers for highly efficient uranium( <scp>vi</scp> ) photoreduction

Herein, the exploration of advanced materials in the highly effective removal of uranium is highly desired. Three amidoxime-functionalized conjugated microporous polymer (CMP-AO) networks with different architectures were synthesized by the Sonogashira-Hagihara coupling reaction. The effect of various factors on the photoreduction of U(VI) on CMP-AO was systemically investigated. The fast photocatalytic efficiency (<i>K</i>₁ = 0.00713 min^-1), superior selectivity and prominent recyclability of U(VI) on CMPs1-AO was achieved due to the outstanding separation of photogenerated carriers, good chemical stability, and massive functional groups. According to trapping and EPR analysis, the photogenerated electrons and superoxide radicals played an important role in U(VI) photoreduction. The introduction of AO groups was shown to be favorable for the photoreduction of U(VI) into U(VI) by XPS analysis. These findings are crucial for the rational design of CMPs in removing U(VI) from aqueous solutions.