空气气氛下光催化辅助提铀技术研究进展  

Progress in Photocatalytic Assisted Uranium Extraction in Air Atmosphere

作　　者：余珊珊 王哲[1] 陈靖[1] 陆跃翔 YU Shan-shan;WANG Zhe;CHEN Jing;LU Yue-xiang(Institute of Nuclear and New Energy Technology,Tsinghua University,Beijing 100084,China)

机构地区：[1]清华大学核能与新能源技术研究院,北京100084

出　　处：《核化学与放射化学》2024年第4期314-324,I0001,共12页Journal of Nuclear and Radiochemistry

摘　　要：光催化辅助提铀技术是近年来快速发展的一种废水和海水提铀技术,其可以显著提升铀的提取容量和提取速率。然而空气气氛下大部分光催化剂的活性受到抑制,阻碍了光催化辅助提铀技术的实用化进程。基于此,本文探讨了空气气氛下光催化辅助提铀技术的最新进展,重点分析了空气气氛下光催化辅助提铀的不同机理及产物特性,尤其是无催化剂情况下的光反应与化学反应机理。相较于光催化还原生成铀氧化物的机理,利用光催化过程产生的过氧化氢将铀酰转化为铀的过氧化物的机理,其产物在空气气氛下更稳定,提铀效率更高,具有更好的实际应用前景。结合对光照条件下铀提取反应机制的探讨以及催化剂材料的设计思考,希望能为研究者开发空气气氛下的高效铀提取催化剂和机理研究提供启示。Photocatalytic assisted uranium extraction technology is a rapidly developed technology for uranium extraction from wastewater and seawater in recent years,which can significantly improve the extraction capacity and extraction rate of uranium.However,the activity of most photocatalysts in air atmosphere is inhibited,which hinders the practical application of this technology.Based on this,this paper discusses the latest progress of photocatalytic assisted uranium extraction technology in air atmosphere,focusing on the analysis of different mechanisms and product characteristics of photocatalytic assisted uranium extraction in air atmosphere,especially the photoreaction and chemical reaction mechanism in the absence of catalyst.There are mainly two mechanisms for the photocatalysis assist uranium extraction.The first one is based on the photocatalytic reduction of U(Ⅵ) to U(Ⅳ).Under illumination,electrons and holes pairs are generated on photocatalysts,and the electrons could reduce the soluble UO_(2)^(2+) to insoluble uranium oxide(UO_(2)).However,under air atmosphere,at the presence of oxygen,the newly formed UO_(2) could be oxidated back to UO_(2)^(2+) and dissolved into solution,resulting in the decrease of uranium extraction performance.Therefore,this mechanism is usually applied under inert atmosphere.Although with proper design of photocatalyst,the oxygen could be covert to ·O_(2)~-to further reduce UO_(2)^(2+),the performance is still not comparable with that under inert atmosphere.The other recently developed photocatalysis assisted extraction mechanism is based on the convert of soluble UO_(2)^(2+) to uranium peroxide((UO_(2))O_(2)·xH_(2)O),which can work well under air atmosphere.Under light illumination,hydrogen peroxide(H_(2)O_(2)) can be first produced with the assist of efficient photocatalysts or the photoactivity of UO_(2)^(2+) itself.Then H_(2O) can react with to UO_(2)^(2+) form insoluble uranium peroxide.As uranium peroxide is stable under air and oxygen may contribute to the formation of

关 键 词：铀富集 海水提铀 空气气氛 反应机理 光催化剂设计 

分 类 号：O615.11[理学—无机化学]