R&D – It can be found in toothpaste, solar cells, and it is useful for chemical catalysts: titanium dioxide (TiO2) is an extremely versatile material. Although it is used for so many different applications, the behaviour of titanium oxide surfaces still surprises.
The surface of titanium oxide is never completely flat. On a microscopic scale, there are tiny steps and edges, many of them with a height of only one atomic layer. At these edges, electrons can localize quite easily.