Spatial microenvironment enhanced photocatalytic reduction of uranyl ions under solar light irradiation

Xingnong Wu; Yishuo Zhang; Lingling Peng; Hao Jiang; Xiaoliang Liu; Shuang Zhang; Muhammad Saeed; Yonghui Liu; Yibao Liu; Tao Bo; Yuhui Liu; Xiaoyan Li

doi:10.1016/j.jhazmat.2024.136708

Spatial microenvironment enhanced photocatalytic reduction of uranyl ions under solar light irradiation

J Hazard Mater. 2024 Nov 29:484:136708. doi: 10.1016/j.jhazmat.2024.136708. Online ahead of print.

Authors

Xingnong Wu¹, Yishuo Zhang¹, Lingling Peng¹, Hao Jiang¹, Xiaoliang Liu¹, Shuang Zhang¹, Muhammad Saeed², Yonghui Liu¹, Yibao Liu¹, Tao Bo³, Yuhui Liu⁴, Xiaoyan Li⁵

Affiliations

¹ National Key Laboratory of Uranium Resources Exploration-Mining and Nuclear Remote Sensing, East China University of Technology, Nanchang 330013, China; Engineering Technology Research Center of Nuclear Radiation Detection and Application of Jiangxi Province, East China University of Technology, Nanchang 330013, China.
² Yangtze Delta Region Institute (Huzhou), University of Electronic Science and Technology of China, Huzhou 313001, China.
³ Zhejiang Key Laboratory of Data-Driven High-Safety Energy Materials and Applications, Ningbo Key Laboratory of Special Energy Materials and Chemistry, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, China. Electronic address: [email protected].
⁴ National Key Laboratory of Uranium Resources Exploration-Mining and Nuclear Remote Sensing, East China University of Technology, Nanchang 330013, China; Engineering Technology Research Center of Nuclear Radiation Detection and Application of Jiangxi Province, East China University of Technology, Nanchang 330013, China. Electronic address: [email protected].
⁵ National Key Laboratory of Uranium Resources Exploration-Mining and Nuclear Remote Sensing, East China University of Technology, Nanchang 330013, China; Engineering Technology Research Center of Nuclear Radiation Detection and Application of Jiangxi Province, East China University of Technology, Nanchang 330013, China. Electronic address: [email protected].

PMID: 39647328
DOI: 10.1016/j.jhazmat.2024.136708

Abstract

Photocatalytic reduction of uranyl ions (UO₂²⁺) is an environmentally friendly, energy efficient, and highly effective method for uranium-containing wastewater treatment and uranium recovery. Herein, a novel photocatalytic material CH-8 @NNFO-4 with abundant oxygen vacancies was synthesize by growing Ca(OH)₂ on the surface of Fe doped NaNbO₃ in situ. The Ca(OH)₂ synergizes with the oxygen vacancies, creating a microenvironment that narrows the bandgap and extends the light response range. At the same time, the Ca-O enhance carrier transport rates and reduce the electron-hole recombination rate. Under solar irradiation, over 93.68 % UO₂²⁺ is rapidly reduced to insoluble U(IV) without protectants or free radical scavengers, which is sixteen times that of pure NaNbO₃, with a theoretical reduction capacity reached to 826.45 mg·g⁻¹. After five cycles, the removal efficiency remains at 88.77 %. The CH-8 @NNFO-4 possesses excellent recyclability, acid and alkali resistant, anti-interference of anions and cations and chemical stability, Furthermore, the charge transfer in CH-8 @NNFO-4 revealed through DFT calculations, and an enhanced mechanism for the Ca-O synergizes spatial microenvironment photocatalytic reduction of U(VI) was proposed. This work provides a new catalytic reaction design strategy for the efficient reduction of U(VI).

Keywords: Oxygen Vacancy; Photocatalytic Reduction; Solar Light Irradiation; Spatial Microenvironment; Uranyl Ions.