Introduction of cation vacancies and iron doping into TiO2 enabling efficient uranium photoreduction

Xiang Gong; Li Tang; Jie Zou; Zhenghong Guo; Yongli Li; Jia Lei; Huanhuan Liu; Min Liu; Li Zhou; Pengling Huang; Haoming Ruan; Yixin Lu; Wenkun Zhu; Rong He

doi:10.1016/j.jhazmat.2021.126935

Introduction of cation vacancies and iron doping into TiO₂ enabling efficient uranium photoreduction

J Hazard Mater. 2022 Feb 5;423(Pt A):126935. doi: 10.1016/j.jhazmat.2021.126935. Epub 2021 Aug 17.

Authors

Xiang Gong¹, Li Tang¹, Jie Zou¹, Zhenghong Guo¹, Yongli Li¹, Jia Lei¹, Huanhuan Liu¹, Min Liu¹, Li Zhou¹, Pengling Huang¹, Haoming Ruan¹, Yixin Lu², Wenkun Zhu³, Rong He⁴

Affiliations

¹ State Key Laboratory of Environment-friendly Energy Materials, National Co-innovation Center for Nuclear Waste Disposal and Environmental Safety, Sichuan Co-Innovation Center for New Energetic Materials, Nuclear Waste and Environmental Safety Key Laboratory of Defense, School of National Defence Science & Technology, Southwest University of Science and Technology, Mianyang, Sichuan 621010, PR China.
² School of Materials and Environmental Engineering, Chengdu Technological University, Chengdu 611730, PR China.
³ State Key Laboratory of Environment-friendly Energy Materials, National Co-innovation Center for Nuclear Waste Disposal and Environmental Safety, Sichuan Co-Innovation Center for New Energetic Materials, Nuclear Waste and Environmental Safety Key Laboratory of Defense, School of National Defence Science & Technology, Southwest University of Science and Technology, Mianyang, Sichuan 621010, PR China. Electronic address: zhuwenkun@swust.edu.cn.
⁴ State Key Laboratory of Environment-friendly Energy Materials, National Co-innovation Center for Nuclear Waste Disposal and Environmental Safety, Sichuan Co-Innovation Center for New Energetic Materials, Nuclear Waste and Environmental Safety Key Laboratory of Defense, School of National Defence Science & Technology, Southwest University of Science and Technology, Mianyang, Sichuan 621010, PR China. Electronic address: her@swust.edu.cn.

PMID: 34461545
DOI: 10.1016/j.jhazmat.2021.126935

Abstract

The reduction of U(VI) to U(IV) in wastewater by semiconductor photocatalysis has become a new highly efficient and low-cost method for U(VI) removal. However, due to the weak absorption of visible light led by wide band gap and low carrier utilization rate resulted from the severe electron-holes recombination, the photoreduction performance of U(VI) is limited. Herein, the Ti vacancies and doped Fe atoms were simultaneously introduced into TiO₂ nanosheet (labeled as 4%Fe-Ti_1-xO₂) as a highly active and stable catalysis for U(VI) photoreduction. Without adding any hole sacrifice agent, 4%Fe-Ti_1-xO₂ nanosheets achieved 99.7% removal efficiency for U(VI) within 120 min. And the 92.1% removal efficiency of U(VI) via 4%Fe-Ti_1-xO₂ nanosheets was still maintained after 5 cycles. Moreover, 4%Fe-Ti_1-xO₂ exhibited dramatic removal rate, 81.6% U(VI) in the solution was removed in 10 min. Further study on the mechanism showed that simultaneously introducing the Ti vacancies and doped Fe atoms in 4%Fe-Ti_1-xO₂ nanosheets improved the visible light utilization and decreased the recombination of photogenerated electron-hole pairs, contributing to the highly efficiency removal of U(VI).

Keywords: Cation vacancies; Fe doping; Photoreduction; TiO(2); Uranium.