Growth of ultralong ZnO nanowires on silicon substrates by vapor transport and their use as recyclable photocatalysts
Growth of ultralong ZnO nanowires on silicon substrates by vapor transport and their use as recyclable photocatalysts
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DOI：
10.1021/cm071568a
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发表时间：
2007-10-16
影响因子：
8.6
通讯作者：
Huang, Michael H.
中科院分区：
文献类型：
--
作者：
Kuo, Tz-Jun;Lin, Chun-Neng;Huang, Michael H.
我们报道了通过金催化气相传输方法在硅（100）衬底上生长超长氧化锌纳米线。在917℃下通过氧化锌粉末的碳热还原产生充足的锌蒸汽以及适量的氧气促进了纳米线的快速生长。这些氧化锌纳米线极长，长度为85 - 100μm，并呈现出整体垂直取向。纳米线的直径大多在250 - 400nm。晶体结构分析表明氧化锌纳米线沿[0001]方向典型生长。这些纳米线的带隙被确定为3.22 eV。这些纳米线在390nm处显示出相对较弱的近带边发射峰，在495nm处有一个明显的与氧空位相关的发射带。证明了这些在衬底上的纳米线对罗丹明B和4 - 氯苯酚的光降解具有良好的光催化活性。此外，我们表明这些在衬底上的纳米线可以作为有效且方便的可回收光催化剂。在光催化实验进行10个循环后，仅观察到光分解速率略有下降。该光催化剂在自然阳光下也能很好地发挥作用。
We report the growth of ultralong ZnO nanowires on silicon (100) substrates via the gold-catalyzed vapor transport approach. An ample supply of zinc vapor generated through carbothermal reduction of ZnO powder at 917 degrees C and a suitable amount of oxygen facilitate the rapid growth of nanowires. These ZnO nanowires are extremely long with lengths of 85 - 1 00,mu m, and exhibit an overall vertical orientation. The nanowires have largely diameters of 250-400 nm. Crystal structure analysis indicates typical ZnO nanowire growth along the [0001] direction. The band gap of these nanowires was determined to be 3.22 eV. These nanowires show a relatively weak near-band-edge emission peak at 390 nm, and a significant oxygen vacancy-related emission band at 495 nm. Good photocatalytic activity of these nanowires on substrates toward the photodegradation of rhodamine B and 4-chlorophenol was demonstrated. Furthermore, we showed that these nanowires on substrates can serve as effective and convenient recyclable photocatalysts. Only a slight decrease in the photodecomposition rate was observed after 10 cycles of the photocatalysis experiment. The photocatalysts also work well under natural sunlight.