Enhanced photocatalytic U(VI) reduction via double internal electric field in CoWO 4 /covalent organic frameworks p-n heterojunction.

Autor: Bi RX; School of Chemistry and Chemical Engineering, Nanchang University, Nanchang 330031, PR China., Peng ZH; School of Chemistry and Chemical Engineering, Nanchang University, Nanchang 330031, PR China., Lei L; School of Chemistry and Chemical Engineering, Nanchang University, Nanchang 330031, PR China., Wang XX; School of Chemistry and Chemical Engineering, Nanchang University, Nanchang 330031, PR China., Liu X; School of Chemistry and Chemical Engineering, Nanchang University, Nanchang 330031, PR China., Zhang L; School of Chemistry and Chemical Engineering, Nanchang University, Nanchang 330031, PR China., Liang RP; School of Chemistry and Chemical Engineering, Nanchang University, Nanchang 330031, PR China. Electronic address: rpliang@ncu.edu.cn., Qiu JD; School of Chemistry and Chemical Engineering, Nanchang University, Nanchang 330031, PR China; State Key Laboratory of Nuclear Resources and Environment, East China University of Technology, Nanchang 330013, PR China. Electronic address: jdqiu@ncu.edu.cn.
Jazyk: angličtina
Zdroj: Journal of hazardous materials [J Hazard Mater] 2024 Aug 15; Vol. 475, pp. 134869. Date of Electronic Publication: 2024 Jun 09.
DOI: 10.1016/j.jhazmat.2024.134869
Abstrakt: Photoreduction of highly toxic U(VI) to less toxic U(IV) is crucial for mitigating radioactive contamination. Herein, a CoWO 4 /TpDD p-n heterojunction is synthesized, with TpDD serving as the n-type semiconductor substrate and CoWO 4 as the p-type semiconductor grown in situ on its surface. The Fermi energy difference between TpDD and CoWO 4 provides the electrochemical potential for charge-hole separation. Moreover, the Coulombic forces from the distinct carrier types between the two materials synergistically facilitate the transfer of electrons and holes. Hence, an internal electric field directed from TpDD to CoWO 4 is established. Under photoexcitation conditions, charges and holes migrate efficiently along the curved band and internal electric field, further enhancing charge-hole separation. As a result, the removal capacity of CoWO 4 /TpDD increases from 515.2 mg/g in the dark to 1754.6 mg/g under light conditions. Thus, constructing a p-n heterojunction proves to be an effective strategy for remediating uranium-contaminated environments.
Competing Interests: Declaration of Competing Interest The authors declare that they have no conflict of interest.
(Copyright © 2024. Published by Elsevier B.V.)
Databáze: MEDLINE
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