石墨相氮化碳改性及其光催化性能研究

发布时间：2018-08-07 19:37

【摘要】：近年来,氮化碳由于价格低廉、环境友好、合成简单和性质稳定等原因,成为了金属材料的良好替代品而引起广泛关注。尤其是石墨相氮化碳,在能源利用方面表现出良好的性质,比如光催化降解有机污染物、光电池和光电解应用。尽管石墨相氮化碳作为光催化剂已趋于成熟,但其电子设备的利用率仍然处于初期阶段。因此,本文通过将g-C_3N_4质子化改善其溶解性,再通过负载、接枝共轭配体来提高其光催化性能。(1)通过热分解双氰胺制备g-C_3N_4,将g-C_3N_4在浓硫酸下剥层实现质子化,得到p-g-C_3N_4。通过XRD和BET对其进行表征及性质研究。结果显示,剥层前后的g-C_3N_4结构没有发生变化,但由于类石墨层的分离,比表面积由原来的7.14 m~2·g~(-1)增加到17.64m~2·g~(-1)。同时,g-C_3N_4质子化后的溶解性能也发生了变化,其可以溶解在DMSO和乙二醇中,且随着溶液温度的升高溶解度增大;(2)以三聚氯氰为桥联剂,将p-g-C_3N_4负载到纤维素包裹的Fe_3O_4磁性微球上,制备得到了p-g-C_3N_4/Fe_3O_4催化剂。通过XRD、IR、VSM、TG等对其进行一系列表征及性质研究。结果显示p-g-C_3N_4/Fe_3O_4具有超顺磁性,可通过外加磁场快速回收。并通过在紫外光下对甲基红的降解效果来研究其催化性能。结果表明,p-g-C_3N_4/Fe_3O_4在90min后甲基红的降解率达到84.26%;(3)以Fe~(3+)为中心离子,咪唑和p-g-C_3N_4为配位体,通过机械研磨的方式制备得到类似于夹心面包的p-g-C_3N_4/Fe_2(SO_4)_3/C_3H_4N_2催化剂。通过XRD、IR、TG等对其进行一系列表征及性质研究。并通过在紫外光下对甲基红的降解效果来研究其催化性能。结果表明,p-g-C_3N_4/Fe_2(SO_4)_3/C_3H_4N_2在90 min后甲基红的降解率达到98.1%.
[Abstract]:In recent years, carbon nitride has become a good substitute for metal materials because of its low price, environmental friendliness, simple synthesis and stable properties. Especially, graphite phase carbon nitride shows good properties in energy utilization, such as photocatalytic degradation of organic pollutants, photocell and photoelectrolysis. Although graphite phase carbon nitride has become mature as photocatalyst, the utilization rate of its electronic equipment is still in its initial stage. In this paper, the solubility of g-C_3N_4 was improved by protonation, and its photocatalytic activity was improved by grafting conjugated ligand. (1) g-C3N _ 4 was prepared by thermal decomposition of dicyandiamide, and g-C_3N_4 was protonated under concentrated sulfuric acid to obtain p-g-C _ 3N _ 4. Their characterization and properties were studied by XRD and BET. The results show that the structure of g-C_3N_4 does not change before and after stripping, but due to the separation of graphite-like layer, the specific surface area increases from 7.14 mg-1 to 17.64m~2 g-1. At the same time, the solubility of tit _ g-C _ 3N _ 4 after protonation also changed, which could be dissolved in DMSO and ethylene glycol, and the solubility increased with the increase of solution temperature. (2) p-g-C_3N_4 was loaded on the Fe_3O_4 magnetic microspheres wrapped in cellulose with cyanuric chloride as bridging agent. P-g-C_3N_4/Fe_3O_4 catalyst was prepared. A series of characterization and properties were carried out by XRDX IR VSMTG and so on. The results show that p-g-C_3N_4/Fe_3O_4 is superparamagnetic and can be recovered quickly by external magnetic field. The catalytic activity of methyl red was studied by the degradation of methyl red under ultraviolet light. The results showed that the degradation rate of methyl-red reached 84.26 after 90min; (3) the p-g-C_3N_4/Fe_2 (SO_4) 3 / C3H4N2 catalyst similar to sandwich bread was prepared by mechanical grinding with Fe3 as the central ion and imidazole and p-g-C_3N_4 as the ligand. A series of characterization and properties were carried out by means of XRD IR TG and so on. The catalytic activity of methyl red was studied by the degradation of methyl red under ultraviolet light. The results showed that the degradation rate of methyl-red reached 98.1 after 90 min.
【学位授予单位】：天津理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O643.36

【相似文献】