The change in the surface potential of TiO2 coatings upon UV-illumination was investigated on the nanoscale using Scanning Kelvin Probe Force microscopy and on the micro-scale using photo-electrochemical measurements. A good correlation between the two techniques was obtained. The changes in the surface potential of TiO2 coatings upon UV-illumination are closely correlated to the band gap and thickness of the coatings. The inhomogeneity surface potential distribution of a 100 nm TiO2 film indicates a heterogeneous coating. Transition to a homogeneous surface potential distribution was observed with increasing thickness of the TiO2 coating.
Daviðsdóttir, S., Dirscherl, K., Canulescu, S., Shabadi, R., & Ambat, R. (2013). Nanoscale surface potential imaging of the photocatalytic TiO2 ﬁlms on aluminum. R S C Advances, 3(45), 23296-23302. https://doi.org/10.1039/c3ra43082k