Paper SS+NS-TuA9
Photodeposited Pt Nanoparticles on Iron Oxide Nanoparticles Supported on Highly Oriented Pyrolytic Graphite

Tuesday, November 11, 2014, 5:00 pm, Room 309

Metal-semiconductor hybrid systems have been of great interest due to their unique photocatalytic properties. In metal-semiconductor hybrid systems, semiconductors are used as light absorbing components. They absorb photons and create electron holes localized at the semiconductor, which are formed by excited electrons that move through the heterointerface. Fe₂O₃ is a promising semiconductor photocatalyst due to its visible light absorption (E_g = 2.2 eV), abundance, non-toxicity, and stability against photo corrosion. However, Fe₂O₃ suffers from short hole diffusion length, low electrical conductivity and high rate of electron hole recombination. To overcome these barriers, different transition metals (e.g. Au, Si, Pt) have been deposited on Fe₂O₃. Particularly, Pt on Fe₂O₃ is an ideal heterogeneous catalyst that has a variety of uses such as photoelectrochemical water splitting and CO oxidation. Importantly, Pt on Fe₂O₃ provides an improvement in photocatalytic properties on the degradation of dyes, such as methylene blue. Although many studies deposit Pt on various forms of Fe₂O₃ (e.g. films, nanorods, and coreshells), Pt nanoparticles on discrete Fe₂O₃ nanoparticles on highly oriented pyrolytic graphite (HOPG) has not been studied. The deposition of Pt on Fe₂O₃ has been studied using various methods such as electrodeposition and solution based synthesis. However, photodeposition of Pt on Fe₂O₃ has not yet been studied. In this work, we demonstrate photodeposition of Pt nanoparticles selectively on Fe₂O₃ nanoparticle arrays formed by physical vapor deposition on HOPG. We find that the Fe₂O₃ nanoparticles are in the range of 7-20 nm in diameter. On-going studies of the catalytic properties of these unique materials will be presented.