Direct growth of ZnO nanocrystals onto the surface of porous TiO(2) nanotube arrays for highly efficient and recyclable photocatalysts.
Direct growth of ZnO nanocrystals onto the surface of porous TiO(2) nanotube arrays for highly efficient and recyclable photocatalysts.
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DOI：
10.1002/smll.200900724
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发表时间：
2009-10
期刊：
影响因子：
13.3
通讯作者：
H. Yang;S. Yu;S. Lau;Xiwang Zhang;D. Sun;Guo Jun
中科院分区：
文献类型：
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作者：
H. Yang;S. Yu;S. Lau;Xiwang Zhang;D. Sun;Guo Jun
近年来，人们对ZnO/TiO 2纳米复合材料的设计和合成进行了广泛的研究，以提高光催化剂在水净化中的量子效率。这是由于TiO 2的高反应活性和ZnO的大结合能，改善了电子和空穴在相应导带和价带之间的转移过程。结果，当与来自单一金属氧化物的催化剂相比时，可以实现光生载体的更好分离。为了提高光催化剂的量子效率，人们提出了ZnO/TiO 2双层结构体系，但由于TiO 2底层的光生电子不能参与光催化反应，导致量子效率降低，因此也提出了ZnO/TiO 2纳米颗粒包覆的四角结构体系，但是两种金属氧化物的总表面暴露面积的较差控制限制了它们作为高效光催化剂的有用性。可替代地，使用
Recently, extensive investigations have been concentrated on the design and synthesis of nanocompositemetal oxides such as ZnO/TiO2 nanocomposite materials to improve the quantum efficiency of photocatalysts for applications in water purification. This is due to the high reactivity of TiO2 and the large binding energy of ZnO, which improve the process of electron and hole transfer between the corresponding conduction and valence bands. As a result, a better separation of photogenerated carriers can be achieved when compared with catalysts from a single metal oxide. A double-layered ZnO/TiO2 system had been proposed to improve thequantumefficiencyofphotocatalysts, however, the photogenerated electrons accumulated in the TiO2 underlayer may be unavailable to participate in the photocatalytic reactions so that the corresponding quantum efficiency could bedegraded.ZnOtetrapods coatedwithTiO2nanoparticles were also suggested for the realization of high efficiency photocatalysts, but the poor control of the total surface exposure area for both metal oxides limited their usefulness as high efficiency photocatalysts. Alternatively, the use of a