金属Mn掺杂对Li_(2)TiO_(3)光催化性能的影响:非辐射耦合作用  

Effect of Metal Mn Doping on the Photocatalytic Performance of Li_(2)TiO_(3):Non-Radiative Coupling Effects

作　　者：樊昊 周颖 代朋 姜文 万财文 李园园 Fan Hao;Zhou Ying;Dai Peng;Jiang Wen;Wan Caiwen;Li Yuanyuan(Department of Tourism and Service Management,Chongqing University of Education,Chongqing,400065;Department of Biological and Chemical Engineering,Chongqing University of Education,Chongqing,400067)

机构地区：[1]重庆第二师范学院旅游与服务管理学院,重庆400065 [2]重庆第二师范学院生物与化学工程学院,重庆400067

出　　处：《化学通报(中英文)》2025年第2期200-211,129,共13页Chemistry

基　　金：国家自然科学基金项目(22209017);重庆市教委科学技术研究项目(KJQN202301613);重庆市自然科学基金项目(CSTB2022NSCQMSX0981);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(S202214388010)资助。

摘　　要：本文采用固相法成功合成了金属Mn掺杂的Li_(2)TiO_(3)氧化物光催化剂,并探究了其在光催化降解2,4-二氯苯酚(2,4-DCP)方面的应用。通过多种测试手段对所制备光催化剂的晶体结构、微观形貌、光学性能和化学组成进行了全面表征。研究发现,尽管Mn掺杂增强了材料对光的吸收,却降低了其体系的光催化效率。稳态荧光表明,Mn掺杂后荧光强度降低,意味着光生载流子分离效率的提升。然而,时间分辨荧光光谱发现Mn掺杂实际上缩短了光生载流子的寿命。理论计算进一步揭示,Mn掺杂形成的Mn-O键,减小了材料的光学带隙,增强了电声耦合及原子核运动速率,从而增加了非辐射耦合系数,这可能是光催化效率下降的关键因素。此外,本研究还利用液相色谱-质谱法(LC-MS)对2,4-DCP的降解途径进行了分析。这项研究为理解掺杂元素在光催化材料性能中的作用提供了重要的理论支持和实验基础。This study successfully synthesized Mn-doped Li_(2)TiO_(3)oxide photocatalysts using the conventional solid-phase method for the photocatalytic degradation of 2,4-dichlorophenol(2,4-DCP).Extensive experiments were performed to characterize the crystal structure,morphology,optical properties and chemical composition of the synthesized photocatalysts.The results reveal that Mn doping enhanced light absorption,but the photocatalytic efficiency was decreased.Steady-state fluorescence experiments indicated a reduction in fluorescence intensity,suggesting improved separation efficiency of photogenerated charge carriers.However,time-resolved fluorescence spectroscopy showed that Mn doping shortened the charge carrier lifetime.Theoretical calculations further exposed that the induced Mn-O bonds reduced the optical bandgap,increased electron-phonon coupling and atomic nuclear motion rates,thereby enhancing the non-radiative recombination coefficient,which could be the critical factors in the decreased photocatalytic efficiency.Additionally,liquid chromatography-mass spectrometry(LC-MS)was employed to analyze the degradation pathways of 2,4-DCP.This research provides significant theoretical and experimental foundations for understanding the role of dopants in the performance of photocatalytic materials.

关 键 词：Li_(2)TiO_(3) Li_(2)MnO_(3) 固溶体 光催化降解 密度泛函理论 非辐射耦合 

分 类 号：O643.36[理学—物理化学]