无机盐工业
主管:中海油天津化工研究设计院有限公司
主办:中海油天津化工研究设计院有限公司
   中海油炼油化工科学研究院(北京)有限公司
   中国化工学会无机酸碱盐专业委员会
ISSN 1006-4990 CN 12-1069/TQ

无机盐工业 ›› 2025, Vol. 57 ›› Issue (10): 139-146.doi: 10.19964/j.issn.1006-4990.2024-0623

• 催化材料 • 上一篇    

层状半导体氧化物Li2MnO3制备及光催化降解2,4-DCP研究

周颖1(), 赖寒2, 代朋2, 彭秦磊2, 郭熙川2, 杨顶峰1(), 李园园2()   

  1. 1.重庆理工大学化学化工学院,重庆 400054
    2.重庆第二师范学院生物与化学工程学院,重庆 400067
  • 收稿日期:2024-11-22 出版日期:2025-10-10 发布日期:2025-05-27
  • 通讯作者: 杨顶峰(1984— ),男,讲师,主要从事无机功能材料的结构、物性及催化的研究;E-mail:yangxunscience@cqut.edu.cn
    李园园(1985— ),女,教授,主要从事无机材料的设计与合成及光催化研究;E-mail:liyy@cque.edu.cn
  • 作者简介:周颖(2000— ),女,硕士研究生,主要从事光催化材料的合成及其应用研究;E-mail:zy1747285407@163.com
  • 基金资助:
    国家自然科学基金项目(22209017);重庆市教委科学技术研究项目(KJZD-K202301605);重庆第二师范学院校级重点项目(KY202307B);重庆市大学生创新创业项目(S202214388024)

Study on preparation of layered semiconductor oxide Li2MnO3 and photocatalytic degradation of 2,4-DCP

ZHOU Ying1(), LAI Han2, DAI Peng2, PENG Qinlei2, GUO Xichuan2, YANG Dingfeng1(), LI Yuanyuan2()   

  1. 1. College of Chemistry and Chemical Engineering,Chongqing University of Technology,Chongqing 400054,China
    2. Department of Biological and Chemical Engineering,Chongqing University of Education,Chongqing 400067,China
  • Received:2024-11-22 Published:2025-10-10 Online:2025-05-27

摘要:

通过固相合成法制备了层状Li2MnO3,并将其应用于光催化降解水中的2,4-二氯苯酚(2,4-DCP)。利用X射线衍射仪(XRD)、透射电子显微镜(TEM)、傅里叶变换红外光谱(FT-IR)表征了光催化剂的形貌与结构,利用紫外-可见漫反射光谱(UV-Vis DRS)和电化学阻抗谱(EIS)分析了光催化剂的光学和电化学性质。研究发现,在900 ℃烧结温度下合成的Li2MnO3样品(LMO-900)展现出优异的光催化性能,30 min内对2,4-DCP的降解率约为87%。紫外-可见漫反射光谱(UV-Vis DRS)和莫特肖特基曲线(Mott-Schottky)表明,Li2MnO3的带隙为2.07 eV,价带电位为1.68 V(vs.NHE),导带电位为-0.39 V(vs.NHE),表明其具有良好的光生电子与空穴还原氧化能力。电化学阻抗谱(EIS)揭示了烧结温度对载流子分离效率的影响,其中LMO-900具有最高的载流子分离效率。自由基捕获实验表明,空穴(h+)和超氧阴离子自由基(∙O2-)是Li2MnO3光催化降解2,4-DCP过程中的主要活性物种。电子结构计算分析表明,Mn—O键是光催化活性中心的关键,对2,4-DCP的降解起着决定性作用。

关键词: 层状氧化物, Li2MnO3, 光催化, 2,4-二氯苯酚

Abstract:

In this study,layered Li2MnO3 was prepared by solid-phase synthesis and applied to the photocatalytic degradation of 2,4-dichlorophenol(2,4-DCP) in water.The morphology and structure of the photocatalysts were characterized using XRD,TEM and FT-IR,and the optical and electrochemical properties were characterized through UV-Vis DRS and EIS.It was found that the Li2MnO3(LMO-900) obtained at a sintering temperature of 900 ℃ exhibited excellent photocatalytic performance,with a degradation efficiency of 2,4-DCP as high as 87% within 30 min.The results of ultraviolet-visible diffuse reflectance spectroscopy(UV-Vis DRS) and Mott-Schottky curves showed that the band gap of Li2MnO3 was 2.07 eV,the valence band potential was 1.68 V(vs.NHE) and the conduction band potential was -0.39 V(vs.NHE),indicating that it had good photogenerated electron and hole redox capabilities.Electrochemical impedance spectroscopy tests revealed the effect of sintering temperature on carrier separation efficiency,among which LMO-900 had the highest carrier separation efficiency.Radical trapping experiments showed that holes(h⁺) and superoxide anion radicals(∙O2-) were the main active species in the process of Li2MnO3 photocatalytic degradation of 2,4-DCP.Electronic structure calculation and analysis showed that the Mn-O bond was the key to the photocatalytic activity centre and played a decisive role in the degradation of 2,4-DCP.

Key words: layered oxides, Li2MnO3, Photocatalysis, 2,4-dichlorophenol

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