Nb2O5纳米线的热氧化生长与光催化性能研究

Investigation on the Thermal Oxidation Growth and Photocatalytic Property of Nb2O5 Nanowires

摘要:

采用热氧化技术在金属铌箔片上生长了Nb2O5纳米线，利用X射线衍射光谱、扫描电子显微镜和透射电子显微镜对产物的物相、形貌和微结构进行表征，并研究了纳米线的光吸收与光催化染料降解特性。结果表明，热氧化所得Nb2O5纳米线为四方相结构，直径约为20-60 nm。当氧气流量为25毫升每分钟（sccm）时，纳米线生长致密、长径比高，构成网络结构。随着氧气流量的增加，纳米线的数量和致密程度逐渐下降。紫外可见吸收光谱表明，Nb2O5纳米线为直接带隙半导体，带隙宽度为3.42 eV。此外，Nb2O5纳米线在波长为365 nm的紫外光照射下对亚甲基蓝、甲基橙和罗丹明B等染料均具有光催化降解性能，效率因子分别为-0.025、-0.021和-0.008 min-1。

Abstract:

Nb2O5 nanowires were synthesized by thermal oxidation process on Nb foils. The phase, morphology and microstructure of the products were characterized by using XRD, SEM and TEM. The optical absorption and photocatalytic dye degradation properties of the nanowires were also investigated. The results show that the sample is composed of pure Nb2O5 with tetragonal structure. The diameter of the nanowires is 20 to 60 nm. When the oxygen flow rate is 25 sccm, the nanowires with high aspect ratio are densely distributed into the network structure. The quantity and density of the nanowires are decreased when the oxygen flow rate is increased. The UV-Vis absorption spectrums show that the Nb2O5 nanowires are direct-band-gap semiconductor with the band gap of ~ 3.42 eV. Under the illumination of UV light with the wavelength of 365 nm, the nanowires exhibit obvious photocatalytic property to methylene blue, methyl orange and rhodamine B, for which the photocatalytic efficiency factor is -0.025, -0.021 and -0.008 min-1, respectively.