Photocatalysis Performance of Nb-doped TiO2 Film in Situ Growth Prepared by a Micro Plasma Method

摘要:

采用微等离子体氧化法，在H2SO4溶液为电解液中以钛合金为基体制备原位生长的TiO2薄膜，并以罗丹明B溶液为目标污染物测试其光催化性能。为提高所得TiO2薄膜的光催化性能，向电解液中添加了不同浓度的草酸铌，制备了原位Nb掺杂TiO2薄膜。利用扫描电镜(SEM)和X射线衍射仪(XRD)分别对Nb掺杂前后的TiO2薄膜表面形貌、元素组成和晶体结构进行了分析。结果表明，Nb掺杂能使介孔TiO2晶粒细化, 比表面积增大，Nb对TiO2晶相组成影响不大，但对晶胞参数有所影响，Nb掺杂可有效提高TiO2的光催化活性, 其中当草酸铌为1.2 g/L时，对初始浓度为10 mg/L罗丹明B溶液90 min的降解率可达到85%, 表现出最强的光降解能力

Abstract:

Thin TiO2 films in-situ grown on titanium alloy substrate were prepared in 0.05 mol/L H2SO4 electrolyte using the micro plasma oxidation method. The photocatalytic properties of the prepared thin TiO2 films were investigated using Rhodamine B solution as a target pollutant. In order to improve the photocatalytic properties of the obtained TiO2 films, different contents of Nb(NO3)3 were added into the H2SO4 electrolyte and the Nb-doped TiO2 films in situ growth were obtained. The influences of the doping ions on the surface morphologies, the crystal phase compositions and microstructures of the TiO2 films were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). The results show that doping of Nb ions can refine the mesoporous TiO2 grain and increase the specific surface area. But doping of Nb ions has little influence on the crystal phase composition and the lattice parameters. Otherwise, doping of Nb ions can improve the photocatalytic activity of TiO2 thin films, when the Nb(NO3)3 is 1.2 g/L, the degradation rate of Rhodamine B solution in 90 min reaches 85%, showing the strongest light degradation ability