The study of local dipole moment and contact potential difference on TiO2 (110) surface by AFM
Yan Jun LI
Osaka University, Japan
: J Nanomater Mol Nanotechnol
Abstract
Au/TiO2 (110) surfaces display extremely high catalytic reactivity. There are many representative models that explain the emerging catalytic activity of Au nanoclusters. It is widely accepted that the perimeter interface of Au/TiO2 is the reaction site for CO oxidation. However, the injection/extraction mechanism of electrons and the reaction process are not clarified by a comprehensive experimental description. In this study, we proposed a new method to simultaneously measuring topography, local contact potential difference (LCPD) and dipole moment distribution on TiO2(110) surface. In the experiment, the DC bias added with AC bias voltage is applied between the tip and sample. Three lock-in amplifiers are used to detect frequency shift of fm, f2m and f3m. The contact potential difference is numerically calculated from the divided result of fm and f2m signals and dipole moment is obtained from frequency shift of f3m . Figure 1 shows the simultaneously measurement result of topography, LCPD and dipole moment images on TiO2 (110) surface. Recent Publications 1. M Haruta (1997) Size- and support-dependency in the catalysis of gold Catalysis Today. 36(1997):153-166. 2. L L Kou, Y J Li, and Y Sugawara (2015) Surface potential imaging with atomic resolution by frequency-modulation Kelvin probe force microscopy without bias voltage feedback. Nanotechnology 26:195701. 3. Takeuchi and H Shigekawa (2007) Kelvin probe force microscopy without bias-voltage feedback. Japanese Journal of Applied Physics 46, 8B. 4. Wen Huan Fei, Y J Li, Arima Eiji, Naitoh Yoshitaka, Sugawara Yasuhiro, Xu Rui and Cheng Zhi Hai (2017) Investigation of tunneling current and local contact potential difference on the TiO2(110) surface by AFM/KPFM at 78 K. Nanotechnology 28, 105704.
Biography
Yan Jun LI is currently working as an Associate Professor at Osaka University, Japan.. liyanjun@ap.eng.osaka-u.ac.jp
