Lu Mingxia, Ohba Tomonori, Kaneko Katsumi, Hata Kenji, Yumura Motoo, Iijima Sumio, Komatsu Hiroto, Sakuma Akira, Kanoh Hirofumi
Department of Chemistry, Graduate School of Science, Chiba University, Chiba 263-8522, Japan.
Research Center for Exotic Nanocarbon (JST), Shinshu University, Nagano 380-8553, Japan.
Materials (Basel). 2013 Feb 15;6(2):535-543. doi: 10.3390/ma6020535.
Electron density of single wall carbon nanotubes (SWCNT) is effectively modified by hexaiodobenzene (HIB) molecules using liquid-phase adsorption. UV-Vis-NIR absorption spectra of the HIB-adsorbed SWCNT, especially in the NIR region, showed a disappearance of S transitions between the V1 valance band and the C1 conduction band of van Hove singularities which can be attributed to the effective charge transfer between HIB and the SWCNT. The adsorption of HIB also caused significant peak-shifts (lower frequency shift around 170 cm and higher shift around 186 cm) and an intensity change (around 100-150 cm and 270-290 cm) in the radial breathing mode of Raman spectra. The charge transfer from SWCNT to HIB was further confirmed by the change in the C1s peak of X-ray photoelectron spectrum, revealing the oxidation of carbon in SWCNT upon HIB adsorption.
通过液相吸附，六碘苯（HIB）分子可有效改变单壁碳纳米管（SWCNT）的电子密度。吸附HIB的SWCNT的紫外-可见-近红外吸收光谱，尤其是在近红外区域，显示出范霍夫奇点的V1价带和C1导带之间的S跃迁消失，这可归因于HIB与SWCNT之间的有效电荷转移。HIB的吸附还导致拉曼光谱的径向呼吸模式出现显著的峰位移动（约170 cm处低频移动和约186 cm处高频移动）和强度变化（约100 - 150 cm和270 - 290 cm处）。X射线光电子能谱的C1s峰的变化进一步证实了从SWCNT到HIB的电荷转移，揭示了HIB吸附后SWCNT中碳的氧化。
