新型Fe掺杂钙钛矿型KMgF_3光催化剂制备及性能  

Synthesis and Properties of a Novel Fe Doped Perovskite-type KMgF_3 Photocatalyst

作　　者：聂坤[1] 杨汉培[1] 孙慧华[1] 崔素珍[1] 吴俊明[1] NIE Kun YANG Hanpei SUN Huihua CUI Suzhen WU Junming(Key Laboratory of Integrated Regulation and Resource Development on Shallow Lakes, Ministry of Education, College of Environment, Hohai University, Nanjing 210098, J iangsu, P. R. China)

机构地区：[1]河海大学环境学院浅水湖泊综合治理与资源开发教育部重点实验室,江苏南京210098

出　　处：《影像科学与光化学》2017年第1期61-69,共9页Imaging Science and Photochemistry

基　　金：国家重大科学仪器设备开发专项(2014YQ060773);江苏省高校优势学科建设工程资助项目;南京领军型科技创业人才引进计划(2014B12007)资助

摘　　要：通过微乳液法制备了Fe掺杂钙钛矿型KMgF_3光催化剂,运用扫描电子显微观察(SEM)、X射线衍射光谱(XRD)、紫外可见漫反射光谱(UV-Vis DRS)、光致发光光谱(PL spectra)、X射线光电子能谱(XPS)等对催化剂形貌、结构及理化特性等进行表征。考察了制备材料对水体中罗丹明B和甲基橙的光降解性能和其稳定性。结果表明,Fe^(3+)通过取代Mg^(2+)掺杂进入KMgF_3晶格形成均质固溶体,抑制晶粒长大和团聚的同时形成新的掺杂能级和浅电子陷阱,显著改善催化剂的光谱响应和抑制催化剂表面光生电子和空穴的复合。最适Fe^(3+)掺杂量为Mg^(2+)的1/4(摩尔分数),掺杂催化剂对水体罗丹明B、甲基橙的降解率30min内分别可达92%、91%,相比未掺杂的催化剂,降解率分别显著提升了约63%、68%。经5次光降解实验循环后,掺杂催化剂活性仍可保持新鲜催化剂的90%以上。The Fe doped perovskite-type Fe-KMgF3 photocatalysts were synthesized by a microemulsion preparation. The as-prepared catalysts were characterized by scanning electron microscope （SEM）, X-ray diffraction （XRD）, UV-Vis diffuse reflectance spectra （UV-Vis DRS）, photoluminescence spectra（PL spectra） and X-ray photoelectron spectroscopy （XPS）. The photocatalytic activity of the materials was performed by the degradation of aqueous Rhodanmine B and Methyl Orange. Results demonstrate that Mg^2＋ in KMgF3 may be substituted by a low amount of Fe^3＋ to form a homogenous solid solution while the perovskite-type structure of KMgF3 remains unchanged. The doping by Fe can suppress the growth and aggregation of KMgF3 crystallion, helps to improve the light response and inhibit the recombination of phtogenerated hole/electron pairs by forming the donor level of impurities and shallow traps in lattice matrix. The photocatalytic degradation rates of Rhodanmine B and Methyl Orange on doped catalyst under optimal content of Fe^3＋ （one quarter of Mg^2＋ ） reached 92% and 91% respectively in 30 min, and about 63% and 68% respectively of degradation rate enhancement which compared with non-doped KMgF3 was observed. After 5th photocatalytic experiment, the photocatalytic degradation rate of Rhodanmine B remains more than 90% of the fresh.

关 键 词：KMGF3 FE掺杂 钙钛矿 罗丹明B 甲基橙 光催化 

分 类 号：O643.36[理学—物理化学]