Department of Physics and Astronomy, University of California, Irvine, California 92697, USA.
Nano Lett. 2010 Mar 10;10(3):896-901. doi: 10.1021/nl9036092.
Individual single-walled carbon nanotubes (SWCNTs) become sensitive to H(2) gas when their surfaces are decorated with Pd metal, and previous reports measure typical chemoresistive increases to be approximately 2-fold. Here, thousand-fold increases in resistance are demonstrated in the specific case where a Pd cluster decorates a SWCNT sidewall defect site. Measurements on single SWCNTs, performed both before and after defect incorporation, prove that defects have extraordinary consequences on the chemoresistive response, especially in the case of SWCNTs with metallic band structure. Undecorated defects do not contribute to H(2) chemosensitivity, indicating that this amplification is due to a specific but complex interdependence between a defect site's electronic transmission and the chemistry of the defect-Pd-H(2) system. Dosage experiments suggest a primary role is played by spillover of atomic H onto the defect site.
当单壁碳纳米管（SWCNTs）的表面被钯金属修饰时，它们会对氢气（H2）变得敏感，之前的报告表明典型的化学电阻增加约为 2 倍。在这里，当钯团簇修饰 SWCNT 侧壁缺陷位置时，电阻的增加达到了千倍。在进行缺陷掺入前后的单根 SWCNT 测量中，证明缺陷对化学电阻响应有非凡的影响，特别是对于具有金属带结构的 SWCNT。未修饰的缺陷对 H2 的化学敏感性没有贡献，这表明这种放大是由于缺陷位点的电子传输和缺陷-Pd-H2 系统的化学之间的特定但复杂的相互依存关系所致。剂量实验表明，原子 H 向缺陷位点的溢出起着主要作用。
