Kelvin Probe Force Microscopy Study of a Pt/TiO2Catalyst Model Placed in an Atmospheric Pressure of N2Environment

Abstract

A catalyst model comprising platinum nanoparticles deposited on a TiO₂(110) wafer was prepared in a vacuum, transferred in air, and characterized with a Kelvin probe force microscope placed in a N₂ environment. The topography and local work function of individual nanoparticles were observed with single‐nanometer resolution in the N₂ environment of one atmosphere pressure. Some nanoparticle presented positive shifts of work function relative to that of the TiO₂ surface, while the others showed negative shifts. This finding suggests heterogeneous properties of the nanoparticles exposed to air and then N₂. The ability of the advanced microscope was demonstrated in observing the work function of metal nanoparticles on a metal oxide support even in the presence of vapor environments.