改性石墨相氮化碳的制备及其可见光催化性能的研究

摘要本论文以焙烧单氰胺制得的体相石墨相氮化碳为前驱体，采用高温刻蚀法制备了石墨相氮化碳纳米片。采用X射线衍射（XRD）、傅里叶变换红外光谱学（FT-IR）、紫外可见漫反射光谱（UV-vis DRS）等表征方法对样品进行了测试分析。结果表明制备的石墨相氮化碳纳米片具有同前驱体石墨相氮化碳相同的晶型组成和化学结构，具有更小的带隙能（2.53eV），拓宽了其可见光吸收范围（~490nm），提高了光生电子空穴的分离效率，从而了提高了石墨相氮化碳纳米片的可见光催化效率。以2,4-二氯苯氧乙酸（2,4-D）为目标污染物，研究其在可见光照射下的光催化活性，结果表明：光照3小时后，浓度降解效率可达80%，说明石墨相氮化碳纳米片相比于石墨相氮化碳，在可见光照射下具有更高的降解速率，具有更高的光催化活性。27664
关键词石墨相氮化碳纳米片可见光催化
毕业论文设计说明书外文摘要
Title Preparation of modified graphitic carbon nitride and study of the photocatalytic activity under visible light irradiation
Abstract
The g-C3N4 nanosheets were prepared by high temperature etching process of bulk g-C3N4 ,which was synthesized by calcining cyanamide directly. The samples were characterized by a variety of techniques, including X-ray diffraction (XRD), Fourier transform infrared spectra (FTIR), and UV/Vis diffuse reflectance spectroscopy. Results showed that g-C3N4 nanosheets basically have the same crystal structure and chemical state as their parent bulk g-C3N4, and possess smaller band gap energy (2.53eV) and wider visible light absorbance range (~490nm). The separation efficiency of photogenerated holes and electron pairs were effectively improved. As a result, the nanosheets showed much superior photocatalytic efficiency under the visible light. The photocatalytic degradation experiments of 2,4-D showed that its degradation efficiency can reach 80% in 3 h. It suggested that g-C3N4 nanosheets have higher photodegradation rate and photocatalytic activity under the visible light irradiation compared with bulk g-C3N4.
Keywords graphitic carbon nitride nanosheets visible-light photocatalysis
目   次　
1 引言   1
1.1 半导体光催化   1
1.1.1 半导体光催化机理   1
1.1.2 半导体光催化影响因素   2
1.2 石墨相氮化碳材料   3
1.2.1 石墨相氮化碳的结构特征   3
1.2.2 石墨相氮化碳的性质   3
1.3 石墨相氮化碳纳米片层   4
1.3.1 石墨相氮化碳纳米片层的特点   4
1.3.2 石墨相纳米片层的常用制备方法   5
1.3.3 石墨相氮化碳纳米片层的研究进展   5
1.4 课题研究意义及内容   6
2 实验部分   7
2.1 实验药品及仪器   7
2.2 材料合成方法   8
2.2.1 石墨相氮化碳的制备   8
2.2.2 石墨相氮化碳纳米片的制备   8
2.3 表征方法   8
2.4 催化剂光催化活性实验   9
2.4.1 光催化反应实验   9
2.4.2 捕获实验   9
2.4.3 重复性实验   9
3 结果与讨论   10
3.1 催化剂表征结果分析   10
3.1.1 TEM分析   10
3.1.2 元素分析   10
3.1.3 AFM分析   11
3.1.4 XRD谱图分析   12 改性石墨相氮化碳的制备及其可见光催化性能的研究:http://www.751com.cn/huaxue/lunwen_22202.html