Direct observation of interstitial titanium ions in TiO2 substrate with gold nanoparticle

Interstitial titanium ions in TiO2 substrates with gold nanoparticle (Au/TiO2) are found to be observable by aberration corrected transmission electron microscopy. The local distribution of the interstitial Ti ions was obtained from TEM images. The interstitial ions are found to exist at a perimeter/interface of Au/TiO2, whereas they are deficient in a peripheral region of the gold nanoparticles. The interstitial ions at the perimeter/interface of Au/TiO2 need attention in CO oxidation catalysis.