具有高催化活性的Ag复合Sm∶ZnO纳米复合材料的制备、表征以及光催化机理研究  

Synthesis,Characterization and Photocatalytic Mechanism of Ag Decorated Sm∶ZnO Nanocomposite with High Photocatalytic Activity

作　　者：马超 余飞 孙翼飞 袁欢[1] 徐明[1] MA Chao;YU Fei;SUN Yifei;YUAN Huan;XU Ming(Key Laboratory of Information Materials of Sichuan Province,School of Electronic Information,Southwest Minzu University,Chengdu 610041,China)

机构地区：[1]西南民族大学电子信息学院,信息材料四川省重点实验室,成都610041

出　　处：《材料导报》2022年第8期42-49,共8页Materials Reports

基　　金：西南民族大学研究生创新型科研项目(CX2020SZ91);国家自然科学基金青年科学基金项目(61901401)。

摘　　要：本工作同时利用稀土元素掺杂和贵金属复合的独特性质对ZnO基复合材料的光学性质以及光催化性能进行调制,采用简便的高分子网络凝胶一步法成功制备了Ag复合Sm∶ZnO纳米复合光催化剂。通过X射线衍射(XRD)、扫描电镜(SEM)、透射电镜(TEM)和X射线光电子能谱(XPS)对Ag复合Sm∶ZnO复合光催化剂进行表征,结果表明,该复合光催化剂具有较好的结晶性和丰富的表面缺陷,Sm以Sm^(3+)的形式进入了ZnO晶格,而Ag以单质的形式复合在ZnO表面。通过紫外-可见吸收光谱(UV-Vis)、光致发光光谱(PL)和表面光电压(SPV)的测试分析表明,Sm掺杂在提升Ag/ZnO对可见光的利用率的同时,还能更好地抑制光生载流子的复合。以亚甲基蓝(MB)作为模拟污染物的光催化实验表明,在模拟太阳光条件下,光照10 min,Ag复合Sm∶ZnO可完全降解MB,其光催化效率是Ag/ZnO的2.44倍。五次循环降解实验验证了其光催化效率的稳定性。对光催化机理的分析表明,Ag复合Sm∶ZnO复合材料光催化性能的提升得益于Sm掺杂和Ag复合的协同效应。一方面,Sm、Ag的同时引入能使样品具有较好的结晶性和丰富的表面缺陷;另一方面,Sm掺杂引入的杂质能级加上Ag复合产生的表面等离子体共振效应在提升催化剂对可见光吸收的同时,也更利于光生电子的有效迁移,实现了光生载流子的更有效分离。The photocatalytic properties of ZnO based composites are regulated by rare-earth metal doping and noble metal decoration simultaneously.Ag decorated Sm∶ZnO nanocomposite photocatalyst can be successfully synthesized by a facile one-step polymeric network gel method in the present work.The X-ray diffraction(XRD),scanning electron microscopy(SEM),transmission electron microscopy(TEM)and X-ray photoelectron spectroscopy(XPS)are used to study the structure,morphology and surface chemical composition of Ag decorated Sm∶ZnO composite.The results show that the composite has good crystallinity and abundant surface defects,and Sm is doped into the lattice of ZnO as Sm^(3+),while Ag is deposited on the surface of ZnO in the form of metal.The results of UV-visible absorption spectrum(UV-Vis),photoluminescence spectra(PL)and surface photo-voltage spectra(SPV)indicate that Sm doping is able to further improve the utilization of the visible light,and further restrain the recombination of photo-generated carriers,compared with Ag/ZnO.The photocatalytic experiments using methylene blue(MB)as the simulated pollutant under simulated sunlight irradiation show that MB can be completely degraded by Ag decorated Sm∶ZnO composite after irradiation for 10 min,and the photocatalytic efficiency is 2.44 times higher than that of Ag/ZnO.What’s more,the stability of photocatalytic efficiency is repeatedly verified by five cyclic degradation experiments.The significantly enhanced photocatalytic properties of Ag decorated Sm∶ZnO composite are due to the synergistic effect of Sm doping and Ag decoration.On the one hand,with the introduction of Sm and Ag,the sample exhibits better crystal quality and abundant surface defects.On the other hand,the impurity energy levels introduced by Sm doping and the surface plasma resonance effect generated by Ag decoration not only improve the absorption of visible light,but also facilitate the migration of photogenerated electrons,thus realizing more efficient photogenerated carrier separation.

关 键 词：高分子网络凝胶法 光催化 Sm掺杂 Ag/ZnO 

分 类 号：O614[理学—无机化学]