南京林业大学.doc

南京林业大学
本科毕业设计(论文)
题目:CoxOy/CdS可见光催化剂的性能研究
学院: 南方学院
专业: 高分子材料与工程
学号: n70804125
学生姓名: 周小双
指导教师: 刘福生
职称: 教授
二O一一年六月一日
摘要
硫化镉是一种优良的光催化剂,它可以有效的降解化工废水中的多数有机物,起到处理废水保护环境的良好作用。但CdS容易被光腐蚀,从而失去活性,降低催化效率。
本文以醋酸镉、硫化钠和乙酸钴为原料,分别制备了CdS纳米光催化剂以及CoxOy/CdS复合半导体光催化剂。用X射线衍射(XRD)对不同煅烧温度和不同煅烧时间制得的CdS纳米光催化剂进行了结构表征。结果表明煅烧温度400℃,煅烧时间4h制备的CdS的晶型最好。无水乙酸钴在400℃煅烧后产物中CoO含量较高,且样品XRD衍射峰较为尖锐,强度较高。
以350W的氙灯为光源,以***橙为模型降解物,研究了复合光催化剂的配比、煅烧温度和煅烧时间对催化剂降解性能的影响。结果表明,CoxOy/CdS复合光催化剂具有更好的光催化性能,当CoxOy的复合量(wt)为5%,煅烧温度400℃,煅烧时间为4h制得的CoxOy/CdS复合催化剂的光催化性能最佳。
关键词:p-n复合半导体;氧化钴;硫化镉;光催化性能
Photocatalytic Activity of CoxOy/pound Semiconductor Photocatalyst under Visible Light
Abstract
CdS is an excellent photocatalyst, which can effectively degrade anic chemicals in waste water and it plays a good role in waste water treatment to protect the environment. However, CdS is easy to be photocorroded, as a result, it will loses its activity and reduces its catalytic efficiency.
In this paper, the nano-CdS and CoxOy/pound photocatalysts were prepared by cadmium acetate, sodium sulfide and cobalt acetate. The structures of nano-CdS prepared at different calcined temperatures and calcined times were characterized by X-ray powder diffraction (XRD). The results showed that the best calcined temperature was 400℃ and the best calcined time was 4h. The product with high content of CoO was prepared by anhydrous cobalt acetate calcined at 400℃ and its XRD pattern showed relatively sharp and higher diffraction peak.
Photocatalytic activities of the samples prepared with different ratios,calcined temperatures and calcined times were investigated by measuring the degradation of methyl orange in aqueous solution under 350W xenon lamp irradiation. The results showed that CoxOy/pound photocatalysts had better photocatalytic activity, and the optimum condition is calcined at 400℃ for 4h with the amount of CoxOy in CoxOy/CdS being 5wt%.
Keywords: p-n coupled semiconductor;CoxOy;CdS;photocatalytic activity
目录
第一章绪论 1
1.