微电极结构Ag／ZnO／NiO三层复合膜的制备及光催化性能的研究

Micro-electrode Ag/ZnO/NiO Tri-layer Film:Preparation and Photocatalytic Activity

通过溶胶-凝胶结合光还原沉积法在普通玻璃片上制备了Ag-ZnO-NiO系复合薄膜。使用SEM,PL,XRD,UV-Vis等手段对薄膜的表面形貌,物相组成及光学性质作了考察和研究。XRD和UV-Vis分析表明复合薄膜中包含NiO和ZnO的双层异质结构;FESEM结果表明Ag和ZnO分别在其各自的衬底上生长但没有形成完全覆盖,PL光谱表明三层膜的发光强度小于双层膜和单层膜。使用甲基橙为模型底物测试了薄膜在紫外线下的光催化氧化能力,结果表明,三层复合薄膜Ag/ZnO/NiO的活性相比氧化锌单层薄膜和双层薄膜有不同程度的提高。这是由于上层薄膜不能完全包裹下层膜,导致在表面形成了许多微电极结构,这些微电极结构能够使光生电子空穴对得到有效分离。

A Ag/ZnO/NiO film was deposited on glass slide using a sol-gel method in combination with photoinduced reduction technique. SEM, PL, XRD and UV-Vis were applied to observe the surface morphology, analyze the composition and their optical properties.The results of XRD and UV-Vis spectroscopy showed that there was a hetero-junction structure composed of NiO and ZnO; FESEM images implied that the layers of silver and zinc oxide were formed and covered incompletely; PL spectra demonstrated that the photoluminescence intensity of the tri-layer film was weaker than those of bilayer or monolayer film. Photocatalyze test using methyl orange as model pollutant and low pressure mercury lamp as irritation source showed that the trilayer film Ag/ZnO/NiO was with a much stronger activity than the monolayer film. Since the inner layers could not be covered completely by the outer ones, there were many micro-electrodes on the surface of the film. Micro-electrodes make it easier for exitons to be separated and result in a higher activity.