Low-Temperature Synthesis and High Visible-Light-Induced Photocatalytic Activity of BiOI/TiO2 Heterostructures
Low-Temperature Synthesis and High Visible-Light-Induced Photocatalytic Activity of BiOI/TiO2 Heterostructures
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BiOI/TiO2 异质结构的低温合成及其高可见光诱导光催化活性
DOI：
10.1021/jp900812d
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发表时间：
2009-04-30
影响因子：
3.7
通讯作者：
Wang, Dejun
中科院分区：
文献类型：
--
作者：
Zhang, Xi;Zhang, Lizhi;Wang, Dejun
通过简单的软化学方法在低至80 ℃的温度下合成了具有不同Bi与Ti摩尔比的BiOI/TiO 2异质结构。采用X射线粉末衍射、电子显微镜、紫外-可见漫反射光谱、氮吸附和X射线光电子能谱等对所制备的粉体进行了表征。在可见光（λ> 420 nm）照射下，以甲基橙橙子为目标染料，研究了BiOI/TiO 2异质结构的光催化活性。结果表明，BiOI/TiO 2异质结构的光催化活性分别比纯BiOI和纯TiO 2高得多，其中50%BiOI/TiO 2的光催化活性最高.表面光电压谱和瞬态光电压测量被用来确认形成的异质结和探针之间的BiOI和TiO 2的电荷转移。BiOI/TiO 2异质结构的可见光催化活性增强可能是由于BiOI和TiO 2之间形成的异质结在可见光区具有较强的吸收和较低的电子-空穴对复合率。
BiOI/TiO2 heterostructures with different Bi to Ti molar ratios were synthesized through a simple soft-chemical method at a temperature as low as 80 degrees C. The as-prepared powders were characterized by X-ray powder diffraction, electron microscopy, UV-vis diffuse reflectance spectroscopy, nitrogen sorption, and X-ray photoelectron spectroscopy. The photocatalytic activities of these BiOI/TiO2 heterostructures were evaluated on the degradation of methyl orange under visible-light irradiation (lambda > 420 nm). The results revealed that the BiOI/TiO2 heterostructures exhibited much higher photocatalytic activities than pure BiOI and TiO2, respectively, and 50%BiOI/TiO2 showed the best activity among all these heterostructured photocatalysts. Surface photovoltage spectroscopy and transient photovoltage measurements were used to confirm the formation of heterojunction and probe charge transfer between BiOI and TiO2. The visible-light photocatalytic activity enhancement of BiOI/TiO2 heterostructures could be attributed to its strong absorption in the visible region and low recombination rate of the electron-hole pairs because of the heterojunction formed between BiOI and TiO2.