[1P01-52] Poster Presentation

[1P18] Effect of UV ozone treatment and annealing on the oleic acid coating of Fe₃O₄ nanoparticles observed by scanning probe microscopy

*Takanori Matsui¹, Miyabi Yonehara¹, Tomoko K. Shimizu² (1. Graduate School of Science and Technology, Keio University, 2. Faculty of Science and Technology, Keio University)

Fe₃O₄ nanoparticles are good catalysts for ammonia synthesis and the water-gas shift reaction. Clarifying the surface structures of Fe₃O₄ nanoparticles at the atomic scale is crucial for understanding catalytic reaction mechanisms. Because Fe₃O₄ nanoparticles are normally functionalized by organic ligands such as oleic acid, the observation of surface structures is challenging. Here we report the investigation of the effect of ultraviolet (UV) ozone treatment and annealing in ultra-high vacuum on the removal of oleic acid from the surface of Fe₃O₄ nanoparticles. Surface structures of the Fe₃O₄ nanoparticles were observed using atomic force microscopy (AFM) and scanning tunneling microscopy (STM). Even after both the UV ozone treatment and annealing, STM images show protrusions separated by 1-2 nm on the surface of nanoparticles, which is larger than the expected atomic arrangement of Fe₃O₄.