[2P01-53] Poster Presentation

[2P14] Optical characterization of Au-supported anatase TiO₂ by using s-SNOM

*Shuki Nakano¹, Kyungmin Kim¹, Jun Nishida², Takashi Kumagai², Masayuki Abe¹ (1. Graduate School of Engineering Science, Osaka University, 2. Center for Mesoscopic Sciences, Institute for Molecular Science)

From the results of SNOM/AFM simultaneous measurements on Anatase and Rutile TiO₂ supported with Au at 2 Å or 4 Å, it was observed that the Au particle radius was dominated in the range of 30 to 40 nm. Additionally, the height of the Au particles was dominated in the range of 13 to 15 nm. The decrease in near-field intensity was found to strongly depend on the height of the Au particles. Given the variation in near-field intensity based on Au NPs size, implications for scattering and absorption efficiencies are suggested. To further clearify these relationships, Kelvin Probe Force Microscopy (KPFM) is necessary. KPFM is a technique that quantitatively measures the potential distribution of a sample by bringing a probe into contact with it. Through KPFM, contact potential difference can be obtained from the measured work function, allowing for the determination of surface potential differences depending on the size of Au-supported TiO₂ nanoparticles. This approach can shed light on the mechanism underlying enhanced catalytic activity by revealing variations in surface electron charge distribution attributed to Au particle size differences.