Abstract
Achieving photoreduction uranium with D-A type conjugated microporous polymers in strongly acidic radioactive wastewater holds great promise but is extremely challenging,as it requires proper electron transport channels.Herein,a redox-active perylene-anthraquinone D-A conjugated microporous polymer photocatalyst(ECUT-AQ)which electron-rich perylene unit as donor and electron-deficient anthraquinone(AQ)as acceptor is innovatively reported.The results clearly demonstrates that AQ with dual characteristics of electron deficiency and redox activity plays a key role in photocatalytic reduction of UO_2~(2+)to UO2.On one hand,the constructed D-A structure induces the formation of a huge built-in electric field,which enhances the intramolecular charge transfer,thus significantly broadening visible light absorption range and improving electron-hole pairs separation efficiency.On the other hand,and very significantly,the redox-active AQ acts as a matched electron transfer channel,which further accelerates the photogenerated electrons transfer from the photocatalyst to the UO_2~(2+).Consequently,the ECUT-AQ achieves 86% photoreduction UO_2~(2+)removal within two hours irradiation and obtains an impressive reduction rate constant(k-0.015 min~(-1),pH=1 and T = 293.15 K).Encouragingly,the current work can enlighten a whole new direction for the subsequent cultivation of more practical metal-free photocatalysts for purification radioactive wastewater.
NSTL