Ag_2CO_3/Ag_2O异质p-n结光催化剂的制备及其可见光光催化性能

Preparation of p-n Junction Ag_2CO_3/Ag_2O Photocatalyst with Enhanced Visible-Light Photocatalytic Activity

采用光分解法成功在Ag2CO3颗粒上制备了Ag2CO3/Ag2O异质p-n结.通过X射线衍射(XRD)、扫描电子显微镜(SEM)、拉曼光谱仪(Raman)和紫外-可见光分光光度计对样品的结构、形貌和光学性能进行表征.以甲基橙(MO)为模型污染物,考察Ag2CO3/Ag2O复合光催化剂在可见光下作用下的光催化性质.结果表明,Ag2CO3/Ag2O异质p-n结能够促进光生电荷的分离,有效提高了Ag2CO3的可见光光催化活性.光催化反应进行80 min后,Ag2CO3/Ag2O复合光催化剂对甲基橙降解率达到86%,而纯Ag2CO3只能降解51%的甲基橙.结果表明表面修饰Ag2O的Ag2CO3复合材料是一种高活性的光催化剂.

The p-n junction Ag2CO3/ Ag2 O photocatalyst for enhancement of visible-light photocatalytic properties has been successfully prepared through a photolysis method. The phase structure, morphology and optical property were characterized by X-ray diffraction（ XRD）,scanning electron microscopy（ SEM）,raman spectrophotometer and UV-Vis spectrophotometer. The photocatalytic properties of the samples were further investigated by the degradation of methyl orange（ MO） under visible light irradiation. The experimental results reshowed that the p-n junction Ag2CO3/ Ag2 O photocatalyst exhibited much higher visible-light photocatalytic activities than the individual Ag2CO3 for the degradation of methyl orange. The enhanced photocatalytic efficiencies were attributed to the charge transfer between n-type Ag2CO3 and the p-type Ag2 O,which reduced the recombination of electrons and holes. After being exposed under visible light for 80 min,86% of MO was degraded by the Ag2CO3/ Ag2 O photocatalyst,while 51% of MO was degraded by the Ag2CO3. The results showed that Ag2CO3 catalyst with the modification of Ag2 O particles was a kind of photocatalytic material with high activities.