Contact Potential Difference of Au/TiO<sub>2</sub>(110) Model Catalysts Measured by Kelvin Probe Force Microscopy

Abstract

Contact potential difference (CPD) of Au/TiO2 model catalysts was measured by Kelvin probe force microscopy (KFM). The CPD of Au particles was lower than that on the TiO2(110) surface and the difference of CPD between them increased with the particle height. By applying the parallel disk model, the work function difference and the charge density at the Au/TiO2 interface were estimated to be 0.19 eV and 0.01 C/m2, respectively. We have previously measured local barrier height (LBH) of Au/TiO2 by scanning tunneling microscopy. From the results of CPD and LBH measurements, we found a possibility that the localized charge at the Au/TiO2 interface plays some role in the catalytic activity of Au catalysts. [DOI: 10.1380/ejssnt.2012.59]