Hydrogen Spillover between Single Gold Nanorods and Metal Oxide Supports: A Surface Plasmon Spectroscopy Study

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• 作者：Sean S. E. Collins ; Michela Cittadini ; Carlos Pecharrom谩n ; Alessandro Martucci ; Paul Mulvaney
• 刊名：ACS Nano
• 出版年：2015
• 出版时间：August 25, 2015
• 年：2015
• 卷：9
• 期：8
• 页码：7846-7856
• 全文大小：639K
• ISSN：1936-086X

文摘

We used dark field spectroscopy to monitor the dissociation of hydrogen on single gold nanoparticles embedded in metal oxide supports. Individual gold nanorods were monitored in real time to reveal the peak position, the full width at half-maximum, and the relative intensity of the surface plasmon resonances during repeated N₂鈥揌₂鈥揘₂ and air鈥揌₂鈥揳ir cycles. Shifts in the spectra are shown to be due to changes in electron density and not to refractive index shifts in the environment. We demonstrate that hydrogen does not dissociate on gold nanorods (13 nm 脳 40 nm) at room temperature when in contact with silica and that electrons or hydrogen atoms migrate from Pt nanoparticles to Au nanoparticles through the supporting metal oxide at room temperature. However, this spillover mechanism only occurs for semiconducting oxides (anatase TiO₂ and ZnO) and does not occur for Au and Pt nanoparticles embedded in silica. Finally, we show that hydrogen does dissociate directly on anatase surfaces at room temperature during air鈥揌₂鈥揳ir cycles. Our results show that hydrogen spillover, surface dissociation of reactants, and surface migration of chemical intermediates can be detected and monitored in real time at the single particle level.