Platinum Nanoparticles on Gallium Nitride Surfaces: Effect of Semiconductor Doping on Nanoparticle Reactivity

Platinum nanoparticles supported on n- and p-type gallium nitride (GaN) are investigated as novel hybrid systems for the electronic control of catalytic activity via electronic interactions with the semiconductor support. In situ oxidation and reduction were studied with high pressure photoemission spectroscopy. The experiments revealed that the underlying wide-band-gap semiconductor has a large influence on the chemical composition and oxygen affinity of supported nanoparticles under X-ray irradiation. For as-deposited Pt cuboctahedra supported on n-type GaN, a higher fraction of oxidized surface atoms was observed compared to cuboctahedral particles supported on p-type GaN. Under an oxygen atmosphere, immediate oxidation was recorded for nanoparticles on n-type GaN, whereas little oxidation was observed for nanoparticles on p-type GaN. Together, these results indicate that changes in the Pt chemical state under X-ray irradiation depend on the type of GaN doping. The strong interaction between the nanoparticles and the support is consistent with charge transfer of X-ray photogenerated free carriers at the semiconductor-nanoparticle interface and suggests that GaN is a promising wide-band-gap support material for photocatalysis and electronic control of catalysis.     «

Platinum nanoparticles supported on n- and p-type gallium nitride (GaN) are investigated as novel hybrid systems for the electronic control of catalytic activity via electronic interactions with the semiconductor support. In situ oxidation and reduction were studied with high pressure photoemission spectroscopy. The experiments revealed that the underlying wide-band-gap semiconductor has a large influence on the chemical composition and oxygen affinity of supported nanoparticles under X-ray irra...     »

ISI Document Delivery No.: 981CH Times Cited: 6 Cited Reference Count: 49 Schaefer, Susanne Wyrzgol, Sonja A. Caterino, Roberta Jentys, Andreas Schoell, Sebastian J. Haevecker, Michael Knop-Gericke, Axel Lercher, Johannes A. Sharp, Ian D. Stutzmann, Martin Jentys, Andreas/D-4622-2009 Jentys, Andreas/0000-0001-5877-5042 Deutsche Forschungsgemeinschaft (DFG) through the TUM International Graduate School of Science and Engineering (IGSSE); Technische Universitat Munchen-Institute for Advanced Study; German Excellence Initiative; EU Marie Curie Initial Training Network We acknowledge the Helmholtz-Zentrum Berlin-Electron storage ring BESSY II for provision of synchrotron radiation at the ISISS beamline and would like to thank Tulio Rocha, Raoul Blume, and Detre Teschner for assistance. The authors thank Peng Jiang of Lawrence Berkeley National Lab for fruitful discussions and Robert Schlogl of Fritz-Haber-Insitut Berlin for insightful comments during the preparation of this manuscript. This work was supported by Deutsche Forschungsgemeinschaft (DFG) through the TUM International Graduate School of Science and Engineering (IGSSE). TEM analysis was performed at the Laboratory of Electron Microscopy, Department of Chemistry, Technische Universitat Munchen. I.D.S. and S.J.S. acknowledge support from the Technische Universitat Munchen-Institute for Advanced Study, funded by the German Excellence Initiative. R.C. acknowledges support from the EU Marie Curie Initial Training Network (FP7/2009-2013). 6 Amer chemical soc Washington     «

ISI Document Delivery No.: 981CH Times Cited: 6 Cited Reference Count: 49 Schaefer, Susanne Wyrzgol, Sonja A. Caterino, Roberta Jentys, Andreas Schoell, Sebastian J. Haevecker, Michael Knop-Gericke, Axel Lercher, Johannes A. Sharp, Ian D. Stutzmann, Martin Jentys, Andreas/D-4622-2009 Jentys, Andreas/0000-0001-5877-5042 Deutsche Forschungsgemeinschaft (DFG) through the TUM International Graduate School of Science and Engineering (IGSSE); Technische Universitat Munchen-Institute for Advanced Stud...     »