Engineering Nanostructured Bi2WO6–TiO2 Toward Effective Utilization of Natural Light in Photocatalysis
Engineering Nanostructured Bi2WO6–TiO2 Toward Effective Utilization of Natural Light in Photocatalysis
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DOI：
10.1111/j.1551-2916.2011.04905.x
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发表时间：
2011-12
影响因子：
3.9
通讯作者：
Yupeng Zhang;L. Fei;Xudong Jiang;C. Pan;Yu Wang
中科院分区：
文献类型：
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作者：
Yupeng Zhang;L. Fei;Xudong Jiang;C. Pan;Yu Wang
作为水和空气净化领域最有前途的光催化剂之一，尽管TiO 2的宽带隙（约3.2 eV的纳米结构）限制了它只能在紫外光照射下活化，但它在全球范围内吸引了广泛的研究兴趣。为了将TiO 2的光催化活性区域向可见光扩展，人们对TiO 2基光催化剂的研究给予了极大的关注。我们在此报告，为第一次，新的“芽上分支”Bi 2 WO 6-TiO 2纳米纤维制造通过一个简单的和大规模的静电纺丝技术从两相前体。Bi 2 WO 6-TiO 2纳米纤维是由直径约为100 nm的锐钛矿-金红石混合体系的TiO 2纳米纤维和约13 nm的Bi 2 WO 6纳米颗粒修饰而成，其比表面积显著增加。相应的光催化实验表明，所设计的异质结构的最佳光催化降解率是纯TiO 2纳米纤维的3倍;这种最佳光降解速率的增加归因于TiO 2和Bi 2 WO 6之间相对良好匹配的能带以及因此在紫外和可见光区域中光生电子-空穴对的优异分离效率，这表明所设计的异质结构可以在自然光下更好地提高实践效率。
Being expected as one of the most promising solutions in water and air purification as photocatalyst, TiO2 is attracting intensive and extensive research interests globally despite its wide band gap (~3.2 eV for anatase structure) which limits it only to be activated under UV irradiation. In pursuit of extending the active region of TiO2 toward visible light, considerable attention was devoted to develop TiO2-based photocatalyst. We report herein, for the first time, novel “bud-on-branch” Bi2WO6–TiO2 nanofibers fabricated via a facile and large-scale electrospinning technique from a biphased precursor. Formed by surface-decorating continuous TiO2 nanofibers (mixed anatase–rutile system with an average diameter of about 100 nm) with ~13 nm well-crystallized Bi2WO6 nanoparticles, the as-synthesized Bi2WO6–TiO2 nanofibers achieved an evidently increased specific surface area. Furthermore, corresponding photocatalytic experiments revealed that the optimal photodegradation rate from our designed heterostructure was as high as three times to that of pure TiO2 nanofibers; this increase in optimal photodegradation rate is attributed to the relatively well-matched energy band between TiO2 and Bi2WO6 and hence an excellent separation efficiency of photogenerated electron–hole pairs in both ultraviolet and visible light regions, suggesting that the designed heterostructures can give better rise to practise photocatalysis under natural light.