ZnO/Ag2O复合光催化剂的制备及其光催化性能研究

Preparation of ZnO/Ag2O Composite Photocatalyst with Ehanced Photocatalytic Activity

以硝酸锌、氢氧化钠为原料,通过微乳法制备得到ZnO纳米棒,然后采用光化学法在ZnO纳米棒表面负载Ag2O纳米颗粒,成功制备了复合光催化剂ZnO/Ag2O。利用X射线衍射仪(XRD)、扫描电子显微镜(SEM)、能谱仪(EDS)、透射电镜(TEM)与紫外可见漫反射(UV-Vis)等手段对样品物相、形貌、元素组成及光学性质进行了表征。并分别在紫外光和可见光条件下,以亚甲基蓝(MB)为模拟污染物评价了催化剂的催化活性。结果表明,与Ag2O耦合后,ZnO的光催化活性得到了明显的提高。ZnO/Ag2O复合光催化剂对亚甲基蓝的紫外光和可见光光催化降解速率分别为ZnO的7.4倍和8.5倍。文章还初步探讨了Ag2O引入对ZnO光催化活性的影响机理。

ZnO nanorods were prepared by microemulsion method with zinc nitrate and sodium hydroxide as the raw materials.And then the ZnO/Ag2O composites were successfully synthesized via a simple photochemical route.The samples were characterized by X-ray diffraction(XRD),scanning electron microscopy(SEM),transmission electron microscopy(TEM),and energy dispersive X-ray spectroscopy(EDS)and UV-Vis spectrophotometer(UV-Vis).Photocatalytic activity toward degradation of a methylene blue(MB)aqueous solution under ultraviolet(UV)light and visible light was investigated.The results showed that the as-prepared ZnO/Ag2O nanocomposites significantly enhanced photocatalytic activity compared with pure ZnO and Ag2O.In particular,the rates of degradation using the as-prepared ZnO/Ag2O nanocomposites were 7.4 and 8.5 times faster than that using bare ZnO nanoparticle under UV and visible light irradiation,respectively.Finally,a possible photocatalytic mechanism was proposed.