Visible light photo-induced antibacterial activity of CNT-doped TiO2 thin films with various CNT contents
Visible light photo-induced antibacterial activity of CNT-doped TiO2 thin films with various CNT contents
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DOI：
10.1039/c0jm00543f
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发表时间：
2010-01-01
影响因子：
--
通讯作者：
Larijani, M. M.
中科院分区：
文献类型：
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作者：
Akhavan, O.;Azimirad, R.;Larijani, M. M.
采用溶胶-凝胶法制备了不同碳纳米管含量的纳米碳管掺杂二氧化钛薄膜，并对其进行了可见光灭活大肠杆菌的研究。在450℃下对碳纳米管掺杂的二氧化钛薄膜进行后处理，得到锐钛矿型的二氧化钛薄膜，并在薄膜中形成了Ti-C和Ti-O-C碳键。随着碳纳米管含量的增加，薄膜可以在黑暗中进一步灭活细菌。同时，当碳纳米管含量从零增加到40wt%时，450℃热处理的碳纳米管掺杂二氧化钛薄膜的有效光学带隙能从3.2-3.3 eV下降到2.8 eV以下，在可见光区提供了光吸收。对此，薄膜表面细菌的可见光光灭活以碳纳米管含量为20wt%为最佳。与100℃热处理的薄膜相比，450℃热处理的掺碳纳米管薄膜对细菌的光失活有进一步的改善。可见光催化性能的提高归因于通过形成的碳键与450℃热处理的薄膜的碳纳米管含量之间的电荷转移，而100℃热处理的薄膜没有这种有效键。
Carbon nanotube (CNT)-doped TiO2 thin films with various CNT contents were synthesized by sol-gel method for visible light photoinactivation of Escherichia coli bacteria. Post annealing of the CNT-doped TiO2 thin films at 450 degrees C resulted in anatase TiO2 and formation of Ti-C and Ti-O-C carbonaceous bonds in the film. By increasing the CNT content, the thin films could further inactivate the bacteria in the dark. Meanwhile, as the CNT content increased from zero to 40 wt% the effective optical band gap energy of the CNT-doped TiO2 thin films annealed at 450 degrees C decreased from 3.2-3.3 to less than similar to 2.8 eV providing light absorption in the visible region. Concerning this, visible light photoinactivation of the bacteria on the surface of the films was found to be optimum for 20 wt% CNT content. The CNT-doped TiO2 thin films annealed at 450 degrees C showed a further improved photoinactivation of bacteria than the films annealed at 100 degrees C. The improvement in the visible light photocatalytic performance was assigned to the charge transfer through the carbonaceous bonds formed between the TiO2 and the CNT content of the films annealed at 450 degrees C, in contrast to the thin films annealed at 100 degrees C which contained no such effective bonds.