摻雜異質(zhì)結(jié)型zno光催化劑的制備及其光催化性能研究

1、I 分類號： 密 級： 公開 公開 學 號： 2009274 單位代碼： 10407 碩 士 學 位 論 文 論文題目: 摻雜/異質(zhì)結(jié)型 ZnO 光催化劑的制備 及其光催化性能研究 研 究 方 向 光催化材料 專 業(yè) 名 稱 應用化學 研 究 生 姓 名 楊 凱 導師姓名、職稱 余長林(副教授) 201 2012 年 6 月 2 日 江西·贛州 III Abstract ZnO is an

2、 important n-type semiconductor, and has the characteristics of its abundant source, non-toxic, and low cost. It has the band gap of 3.2 eV. Under the irradiation of ultraviolet light, ZnO will can produce photogenerated

3、 electron-hole pairs, and further transform to generate the high active groups such as · OH and · O2- with strong oxidization and reduction abilities, which can be used for the degradation of the organic pollut

4、ants such as dyes. Now, it gradually attracts great attention of the domestic and foreign photocatalytic researchers. However, Compared with the already commercialized TiO2 photocatalyst, ZnO has its disadvantage due to

5、its lower photocatalytic activity and photocatalytic stability. Low photocatalytic activity is caused by the high recombination rate of the photogenerated electron-hole pairs. Low photocatalytic stability was resulted by

6、 the photochemistry corrosion. These disadvantages limites its large-scale industrial utilization.Therefore, it is a research focus to improve its photocatalytic activity and stability by design the composition and struc

7、ture of ZnO in the photocatalytic field. In view of the photocatalytic shortcomings of ZnO as a photocatalyt, the effects of elment doping and the formation of heterojunction on the physical struture and photocatalytic p

8、erformance of ZnO were investigated. The photocatalytic activity of the samples was evaluated by the photodegradation of acid orange II or methylene blue. The relationship between the composition,structure of ZnO and pho

9、tocatalytic properties were discussed. The major research contents are as follows: 1. The effects of doing typical rare earth metal ions and transition metal ions on the structure and photocatalytic property of ZnO were

10、investigated. The influences of the donging content of Ce and Sn and the preparation conditions on the structure property such as the crystal, optical absorption and photocatalytic performance of ZnO were explored. The i

11、nfluence of the structure and photocatalytic performance resulting form Zr-Al codoped ZnO was also discussed. Results showed that the surface property of ZnO was modified and more surface hydroxyl groups could produce. T

12、he doping could effectively promote the separation of electron-hole pairs, which contribute to a big improvement of photocatalytic performance. 2. The effects of the formation of heterojunction structure over ZnO by cou

13、pling with the typical semiconductor on the structures and photocatalytic performance of ZnO were investigated. Firstly, the influence of WO3/ZnO heterojunction structure on the structure, surface properties and photocat

14、alytic performaces of ZnO was investigated. It is found that the presence of WO3 could effectively inhibit the growth of ZnO crystal and increase its specific surface area and the surface hydroxyl groups. The recombinati