Asymmetric and symmetric absorption peaks observed in infrared spectra of CO2 adsorbed on TiO2 nanotubes

作者：Yamakawa Koichiro^*; Sato Yoshinori; Fukutani Katsuyuki

来源：Journal of Chemical Physics, 2016, 144(15): 154703.

DOI：10.1063/1.4946790

Infrared spectra of CO2 physisorbed on titania nanotubes (TiNTs), predominantly in the anatase polymorph, were measured at 81 K. Asymmetric and symmetric absorption peaks due to the anti-symmetric stretch vibration (nu(3)) of CO2 were observed at 2340 cm(-1) and 2350 cm(-1), respectively. On the basis of the exposure-and time-dependence of the spectrum, the 2340 cm(-1) peak was attributed to CO2 at the defective sites related to subsurface O vacancies (V(o)s) while the 2350 cm(-1) peak was assigned to that at the fivefold coordinated Ti4+ sites. It was found that the generalized Fano line shape was well fitted to the 2340 cm(-1) peak. We also observed an absorption peak at 2372 cm(-1), which was attributed to the combination band of nu(3) and the external mode of CO2 at Ti4+. Published by AIP Publishing.

• 出版日期2016-4-21