Titanium Dioxide Surfaces Investigated by Atomic Force Microscopy

Titanium dioxide (TiO2) surfaces have been extensively studied for its broad range of applications such as photocatalysis, heterogeneous catalysis, gas sensors, and solar cells. Rutile TiO2 has also been investigated as a model system for studying the physical and chemical properties for studying more complex metal oxide surfaces. Here, we report studies of atomic-scale observation of TiO2 surfaces by atomic force microscopy (AFM). While AFM imaging mechanism on TiO2(110) has been understood well, we find the interpretation of AFM contrast on TiO2(011) is not straightforward. In addition, we also perform simultaneous AFM and Kelvin probe force microscopy (KPFM) measurements on subsurface charges and single Pt atoms on the TiO2(110) surfaces, respectively. We believe our findings in this report will be useful when investigate other catalytic system by AFM and KPFM