Oxygen isotope exchange between carbon dioxide and solid Ti18O2

Titanium dioxide is an attractive material for (photo)catalysis, solar cells, electrochromics and batteries, while various fundamental studies would benefit from the accessibility of a totally ¹⁸O exchanged material. For instance, O-isotope labeling would allow deeper discussion of Raman spectra, because the presence of heavier oxygen atom in the crystal lattice of titania (anatase, rutile) influences differently various Raman active vibrations of the lattice. Second motivation for synthesis of Ti¹⁸O₂ was the investigation of surface effects during titania/gas interaction. Here we report, for the first time, the preparation of pure Ti¹⁸O₂ both in anatase and rutile forms. Raman spectroscopy indicated various isotope shifts for the known vibration modes of titania (anatase, rutile). The interaction with carbon dioxide was investigated with the aim to explore oxygen isotope exchange at the Ti¹⁸O₂/CO₂ interface. For this purpose, high-resolution Fourier transform infrared spectroscopy of the gas phase was adopted.