Guo Yadan, Li Shuaihang, Yang Fan, Li Chenxi, Guo Yaoping, Xuan Keng, Wang Guanghui, Liu Yunhai, Li Jun
State Key Laboratory of Nuclear Resources and Environment, East China University of Technology, Nanchang 330013, China; School of Water Resources & Environmental Engineering, East China University of Technology, Nanchang 330013, China.
School of Water Resources & Environmental Engineering, East China University of Technology, Nanchang 330013, China.
J Hazard Mater. 2022 Oct 15;440:129734. doi: 10.1016/j.jhazmat.2022.129734. Epub 2022 Aug 8.
Photocatalytic reduction of U(VI) in aqueous solutions has been considered as an efficient and promising technology to solve radioactive U pollution. In this work, density functional theory (DFT) calculations were firstly employed to optimize and compare the adsorption configurations combined uranium with four given photocatalysts, then their adsorption energies were - 0.97 eV for AgFeO, - 1.15 eV for Zn doped AgFeO, - 1.73 eV for Cu doped AgFeO and - 2.66 eV for S doped AgFeO, respectively, indicating the sulfur doping plays a major role in U(VI) photoreduction. Herein, a visible light responsive efficient sulfur doped AgFeO photocatalyst (S doped AgFeO) was synthesized and utilized to photocatalytic reduction of U(VI) in aqueous solutions. According to XRD, XPS and TEM analysis, the sulfur was successfully doped in AgFeO via the hydrothermal method. The batch experimental showed that S doping enhanced the U(VI) photoreduction activity of AgFeO, and the S-AFO-3 photocatalyst exhibited the highest photocatalytic activity (92.57%), which was 1.5 times than that of pure AgFeO. ESR, PL and DFT results demonstrated that the enhancement of adsorbed U(VI) photoreduction was attributed to the own unique effect of oxygen vacancy defects and efficient charge separation of S doped AgFeO photocatalyst. Due to its higher adsorption energies, fast-U(VI) photoreduction rate and superior chemical stability, the sulfur doped AgFeO photocatalyst is hoped for water remediation containing U(VI) wastewater.
光催化还原水溶液中的U(VI)被认为是解决放射性U污染的一种高效且有前景的技术。在本工作中，首先采用密度泛函理论(DFT)计算来优化和比较四种给定光催化剂与铀的吸附构型，然后它们的吸附能分别为AgFeO的-0.97 eV、Zn掺杂AgFeO的-1.15 eV、Cu掺杂AgFeO的-1.73 eV和S掺杂AgFeO的-2.66 eV，表明硫掺杂在U(VI)光还原中起主要作用。在此，合成了一种可见光响应的高效硫掺杂AgFeO光催化剂(S掺杂AgFeO)，并用于光催化还原水溶液中的U(VI)。根据XRD、XPS和TEM分析，通过水热法成功地将硫掺杂到AgFeO中。批量实验表明，S掺杂增强了AgFeO对U(VI)的光还原活性，S-AFO-3光催化剂表现出最高的光催化活性(92.57%)，是纯AgFeO的1.5倍。ESR、PL和DFT结果表明，吸附的U(VI)光还原增强归因于氧空位缺陷的独特作用和S掺杂AgFeO光催化剂的有效电荷分离。由于其较高的吸附能、快速的U(VI)光还原速率和优异的化学稳定性，硫掺杂AgFeO光催化剂有望用于含U(VI)废水的水修复。
