Addressing the challenges of uranium extraction from seawater(UES)requires innovative strategies to overcome ultralow concentration(3.3 ppb)and thermodynamic limits.Herein,we propose a regioisomeric engineering strate...Addressing the challenges of uranium extraction from seawater(UES)requires innovative strategies to overcome ultralow concentration(3.3 ppb)and thermodynamic limits.Herein,we propose a regioisomeric engineering strategy to design vinylene-linked covalent organic frameworks(COFs)for synergistic adsorption-photocatalytic UES.Two isomeric COFs,β-PTTN-AO andα-PNNB-AO,were synthesized by tuning the substitution positions of amidoxime(AO)groups on olefin bonds.Theβ-PTTN-AO isomer achieves a remarkable UES capacity of 12.74±0.21 mg·g^(-1)in nature seawater,surpassing itsα-positioned counterpart(8.9±0.18 mg·g^(-1))and outperforming most reported photocatalysts.Combined experiments and density functional theory(DFT)theoretical studies correlate regioisomeric configurations with electronic structure modulation and photocatalytic activity.Specifically,β-PTTN-AO enhanceπ-electron delocalization and strengthen built-in electric fields,promoting exciton dissociation,charge separation,and uranium reduction.This work establishes a molecular design paradigm for COF photocatalysts,advancing sustainable nuclear energy through structural isomerism.展开更多
基金National Natural Science Foundation of China(Nos.22465001,22105034,22202039, 22466003)Young Elite Scientists Sponsorship Program by JXAST(No.2024QT11)+2 种基金the Jiangxi Provincial Natural Science Foundation(Nos.20232BAB203042,20242BAB22002,20242BAB23023)the Academic and Technical Leaders of Major Disciplines in Jiangxi Province(No.20232BCJ23017)the Graduate Innovation Fund of East China University of Technology(No.DHYC-202420).
文摘Addressing the challenges of uranium extraction from seawater(UES)requires innovative strategies to overcome ultralow concentration(3.3 ppb)and thermodynamic limits.Herein,we propose a regioisomeric engineering strategy to design vinylene-linked covalent organic frameworks(COFs)for synergistic adsorption-photocatalytic UES.Two isomeric COFs,β-PTTN-AO andα-PNNB-AO,were synthesized by tuning the substitution positions of amidoxime(AO)groups on olefin bonds.Theβ-PTTN-AO isomer achieves a remarkable UES capacity of 12.74±0.21 mg·g^(-1)in nature seawater,surpassing itsα-positioned counterpart(8.9±0.18 mg·g^(-1))and outperforming most reported photocatalysts.Combined experiments and density functional theory(DFT)theoretical studies correlate regioisomeric configurations with electronic structure modulation and photocatalytic activity.Specifically,β-PTTN-AO enhanceπ-electron delocalization and strengthen built-in electric fields,promoting exciton dissociation,charge separation,and uranium reduction.This work establishes a molecular design paradigm for COF photocatalysts,advancing sustainable nuclear energy through structural isomerism.
