摘要本文以Bi(NO3)3和Fe(NO3)3为原料，通过一步水热法制备了磁性Bi25FeO40，通过单氰胺和硅溶胶制备了介孔石墨相氮化碳，并按照不同比例将二者复合制备mpg-C3N4/Bi25FeO40复合催化剂。通过XRD、SEM和磁性测试对样品进行结构特性的研究结果表明，mpg-C3N4/Bi25FeO40复合催化剂具有mpg-C3N4和Bi25FeO40各自的晶型结构，且Bi25FeO40呈立方状结构；50% mpg-C3N4/Bi25FeO40具有良好的磁性，可通过磁选分离。63858

将50% mpg-C3N4/Bi25FeO40复合催化剂用于亚甲基蓝、甲基橙和中性红的光催化降解实验发现，该催化剂对于三种染料污染物均具有一定的光催化降解效率，其中亚甲基蓝的降解效率最高。进一步研究mpg-C3N4/Bi25FeO40复合催化剂降解亚甲基蓝过程的影响因素可知，随着催化剂投加量的增加，MB的降解率增加，但是催化剂初始反应速率下降；MB溶液浓度升高，MB的降解率下降，但催化剂初始反应速率升高；pH值的变化对催化剂性能的影响不明显，相比而言，中性条件更利于催化反应的进行。

毕业论文关键词：mpg-C3N4；Bi25FeO40；可见光催化；复合磁性材料

毕业设计说明书（论文）外文摘要

Title   Visible-light induced mpg-C3N4/Bi25FeO40 composite  catalyst and its photocatalytic performance

Abstract In this paper, we used Bi(NO3)3 and Fe(NO3)3 as raw material to prepare magnetic Bi25FeO40 by using hydrothermal, we also used cyanamide and Silica Sol to prepare mesoporous graphitic carbon nitride (mpg-C3N4). Then we compound the two samples in different proportion to prepare visible light-induced mpg-C3N4/Bi25FeO40 composite photocatalysts. The obtained mpg-C3N4/Bi25FeO40 products were characterized by X-ray diffraction, scanning electron microscopy and Magnetic Testing. The result show that Bi25FeO40 has cubic structure, 50% mpg-C3N4/Bi25FeO40 composite photocatalysts have both crystal structure of mpg-C3N4 and Bi25FeO40; 50% mpg-C3N4/Bi25FeO40 composite photocatalysts has good magnetic properties, it could be separated from reaction system through magnetic separation.

The photocatalytic oxidation ability of the photocatalysts was evaluated by using methylene blue (MB), methyl orange (MO) and neutral red (NR) as target pollutants. The photocatalysts had certain photocatalytic degradation efficiency for all the three dyes, in which the degradation of MB has the maximum efficiency. Further research show that with the increase of catalyst dosage, MB degradation rate increased, while the catalyst activity decreased. The increase of MB solution concentration lead to the decrease of MB degradation rate and enhanced catalyst activity. The changes of pH value just have little effect on catalyst performance.

Keyword：mpg-C3N4；Bi25FeO40；photocatalytic；composite magnetic material

1  引言 1

1.1  光催化技术及其反应机理 1

1.2  g-C3N4概述及其光催化研究进展 4

1.3  Bi25FeO40概述及其光催化研究进展 5

1.4  水热法概述 6

2  实验部分 7

2.1  实验试剂与仪器 7

2.1.1  实验试剂 7

2.1.2  模拟废水所用染料 8

2.1.3  实验仪器 8

2.2  光催化剂的合成与表征 9

2.2.1  Bi25FeO40的制备 9

2.2.2  介孔石墨相氮化碳（mpg-C3N4）的制备 9