论文总字数：18293字

摘 要

近年来，由于半导体光催化技术在降解有机污染物方面十分高效，因而激发了很多人的研究兴趣。而寻找禁带宽度窄、高量子效率和高稳定性的光催化剂，是该技术的关键工作。石墨相氮化碳在最近几年吸引了很多研究者们的目光，其在利用太阳能降解环境污染物中表现突出。然而，因为纯C₃N₄带隙较窄，比表面积较低，太阳光吸收范围较小，且其光生电子空穴对易复合，光催化效率往往较低，在光催化领域中的应用受到了一定阻碍。因此，选择合适的半导体与C₃N₄结合构成复合材料，可以有效扩大其可见光的吸收范围，同时提高光催化稳定性，从而拓展其在光催化降解有机污染物的应用范围。

尖晶石型ZnFe₂O₄纳米材料由于其禁带宽度小、光化学稳定性较强以及对可见光的响应能力强等优点，被认为是一种发展前景很好的新型半导体光催化材料。本论文首先以C₃H₆N₆为原料，采用热分解的方法制备石墨相氮化碳，然后以二水合锕化锌、六水合氯化铁为主要原料，通过溶剂热法制备铁酸锌纳米颗粒后，最后采用水热法成功合成g-C3N4/ZnFe2O4复合样品，通过一系列分析方法对材料进行了结构形貌等方面的分析，实验所得样品ZnFe₂O₄的形貌为纳米粒子，其外形为球状，粒径均一，粒径尺寸在20~30nm左右。通过测定材料在不同实验条件下降解有机污染物RhB的速率来表征其光催化性能。根据实验所得数据可知，本实验中制得的g-C₃N₄/ZnFe₂O₄样品对RhB降解性能优于g-C₃N₄和ZnFe₂O₄，在光照180min时几乎将RhB完全降解。由此可推断出，ZnFe₂O₄和g-C₃N₄的结合对促进光生电子和空穴的分离有明显作用，提高了光生载子的产率，进而改善了其光催化效率。

关键词：C₃N₄/ ZnFe₂O₄、复合光催化剂、罗丹明B

Preparation and Photocatalytic Activity of C₃N₄/ZnFe₂O₄ Nanocomposite Photocatalytic Materials

Abstract

In recent years, semiconductor photocatalytic technology has been very efficient in degrading organic pollutants, which has stimulated many people's research interests. The search for photocatalysts with narrow band gaps, high quantum efficiency and high stability is a key task of this technology. Graphite-phase carbonitride has attracted the attention of many researchers in recent years, and it has been outstanding in the use of solar energy to degrade environmental pollutants. However, because pure C₃N₄ has a narrow band gap, a low specific surface area, a small solar absorption range, and a photogenerated electron-hole pair is easy to recombine, the photocatalytic efficiency tends to be low, and its application in the field of photocatalysis is hindered. . Therefore, selecting a suitable semiconductor to combine with C₃N₄ to form a composite material can effectively expand the absorption range of visible light and improve the photocatalytic stability, thereby expanding its application range in photocatalytic degradation of organic pollutants.

Spinel-type ZnFe₂O₄ nanomaterials are considered to be a new type of semiconductor photocatalytic material with good development prospects due to its small band gap, strong photochemical stability and strong response to visible light. In this thesis, the graphite phase carbonitride carbon was prepared by thermal decomposition method using C₃H₆N₆ as raw material, and then zinc ferrite nanoparticle was prepared by solvothermal method using zinc hydride dihydrate and ferric chloride hexahydrate as main raw materials. The composite sample of g-C₃N₄/ZnFe₂O₄ was successfully synthesized by hydrothermal method. The structure and morphology of the material were analyzed by a series of analytical methods. The morphology of the sample was ZnFe₂O₄. The shape of the sample was spherical and the particle size was uniform. The particle size is about 20~30nm. The photocatalytic performance of the organic pollutant RhB was characterized by measuring the rate at which the material degraded the organic pollutant RhB under different experimental conditions. According to the experimental data, the g-C₃N₄/ZnFe₂O₄ sample prepared in this experiment has better degradation performance to rhodamine B than g-C₃N₄ and ZnFe₂O₄, and RhB is almost completely degraded when exposed to light for 180 min. It can be inferred that the combination of ZnFe₂O₄ and g-C₃N₄ has a significant effect on promoting the separation of photogenerated electrons and holes, and improves the yield of photogenerated carriers, thereby improving the photocatalytic efficiency.

KEY WORDS：C₃N₄/ ZnFe₂O₄, composite photocatalyst, rhodamine B

目 录

摘 要 I

Abstract II

第一章 绪论 1

1.1引言 1

1.2光催化材料及其反应机理 2

1.3 g-C₃N₄光催化剂的概述 3

1.3.1 g-C₃N₄光催化剂的结构 3

1.3.2 g-C₃N₄ 光催化剂的应用 4

1.3.3 g-C₃N₄ 光催化剂的改性 4

1.4 ZnFe₂O₄光催化剂的概述 4

1.4.1 ZnFe₂O₄光催化剂的结构 5

1.4.2 ZnFe₂O₄光催化剂的应用 5

1.4.3 ZnFe₂O₄光催化剂的制备 5

1.5 本文的选题思路及主要研究内容 6

第二章 实验部分 7

2.1 实验试剂与仪器 7

2.2 实验步骤 7

2.2.1 g-C₃N₄的制备 7

2.2.2 ZnFe₂O₄纳米颗粒的制备 7

2.2.3 g-C₃N₄/ZnFe₂O₄的制备 8

2.3材料结构形貌的表征 9

2.3.1 XRD分析 9

2.3.2扫描电镜和透射电镜分析 10

2.3.3紫外可见吸收光谱测试 11

2.3.4氮气吸脱附测试 11

2.3.5荧光光谱 12

2.4材料性能测试 12

第三章 实验结果与讨论 13

3.1晶体结构分析 13

3.1.1 X射线衍射（XRD）分析 13

3.1.2扫描电镜（SEM）和透射电镜(TEM)分析 13

3.1.3 比表面测试 14

3.1.4紫外可见光谱图分析 15

3.1.5光致发光光谱（PL）分析 16

3.2光催化性能分析 17

第四章 结论与后期规划 19

4.1结论 19

4.2 后期规划 19

请支付后下载全文，论文总字数：18293字