Photocatalytic reduction and removal of toxic uranium(VI) from aqueous solution is a highly economic, non-pollutant and efficient strategy. However, most uranium containing waste waters are highly acidic, but current photocatalysts are still restricted in slightly acidic or neutral media (pH ≥ 4). Herein, a conjugated microporous polymer (CMP), pTTT-Ben, was used for visible light driven photocatalytic reduction of U(VI) in highly acidic condition (pH = 1). A high uranium removal capacity (4710 mg/g) was achieved. The structural information of reduced uranium was investigated by X-ray photoelectron spectroscopy (XPS) and extended X-ray absorption fine structure (EXAFS), revealing the amorphous U(IV) hydrate complex, with an additional interaction between U(IV) and nitrogen atoms on pTTT-Ben. In addition, pTTT-Ben also showed excellent photocatalytic U(VI) reduction performance under natural sunlight irradiation.
Keywords: conjugated microporous polymer; photocatalysis; uranium(VI) reduction; visible light.
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