氮等离子体掺杂对ZnO/TiO2核壳纳米棒可见光催化性能的影响

Effects of Nitrogen Plasma Doping on Visible Light Photocatalytic Performance of ZnO/TiO2 Core-Shell Nanorods

采用水热法和液相沉积法制备了ZnO/TiO2核壳纳米棒阵列,并利用电子回旋共振微波等离子体对其进行N掺杂。利用SEM、TEM、XRD、XPS对其形貌和结构性能进行表征,研究了N掺杂对其晶体结构、元素组成和表面电子态的影响。利用紫外可见分光光度计和光催化性能测试装置对其光学性能和可见光催化性能进行了研究。结果表明,N掺杂未对晶体结构产生明显影响,掺杂N在TiO2中主要以替位掺杂的方式存在。随着等离子体工作气压的降低,替位掺杂N的浓度随之增加,而带隙宽度却随之减小。研究发现,N掺杂ZnO/TiO2核壳纳米棒阵列的可见光催化活性随着替位掺杂N浓度的增加而增强,并基于能带理论对可见光催化性能增强机制进行了讨论。

ZnO/TiO2 core-shell nanorod arrays were prepared via hydrothermal method and liquid phase deposition.Then N-doped ZnO/TiO2 core-shell nanorod arrays were obtained by ECR nitrogen plasma.The morphology and structural properties were characterized by SEM,TEM,XRD,XPS,and the effect of nitrogen doping on its crystalline structure,element composition,and surface electronic state were studied.The optical performance and visible light photocatalytic performance were investigated using ultraviolet-visible spectrophotometer and photocatalytic performance testing device.The results indicate that nitrogen plasma treatment has no significant impacts on the crystalline structure of the nanorods and the nitrogen exists mainly in the form of substitutional N.With the decrease of the working pressure,the concentration of the substitutional N increases,while the optical bandgap of the nanorod arrays decreases.The photocatalytic activity tests show that the visible light photocatalytic efficiency of the N-doped ZnO/TiO2 core-shell nanorod arrays increases with the concentration of the substitutional N.Based on the energy band theory,the enhancement mechanism of visible light photocatalytic performance was discussed.