Preparation of TiO2 Nanocrystallites by Oxidation of Ti-Au(111) Surface Alloy

Ti-Au surface alloy oxidation is used to form nanocrystals of TiO2 on Au(111). In situ scanning tunneling microscopy (STM) studies show that the approach yields arrays of 8-11 nm wide crystals with relatively narrow size dispersion and uniform crystallography. STM imaging shows that their crystallographic form is rutile with a triangular or hexagonal geometry. Scanning tunneling spectroscopy indicates that the crystals have a well-developed band gap, comparable to that in bulk TiO2.