Endogenous Stable Radicals for Characterization of Thermally Carbonized Porous Silicon by Solid-State Dynamic Nuclear Polarization 13C NMR

详细信息    查看全文

• 作者：Joakim Riikonen ; S茅verinne Rigolet ; Claire Marichal ; Fabien Aussenac ; Jacques Lalev茅e ; Fabrice Morlet-Savary ; Philippe Fioux ; C茅line Dietlin ; Magali Bonne ; B茅n茅dicte Lebeau ; Vesa-Pekka Lehto
• 刊名：Journal of Physical Chemistry C
• 出版年：2015
• 出版时间：August 20, 2015
• 年：2015
• 卷：119
• 期：33
• 页码：19272-19278
• 全文大小：357K
• ISSN：1932-7455

文摘

As with all nanomaterials, characterization of the surface chemistry of mesoporous silicon (PSi) is crucial for the development in its diverse applications. Nuclear magnetic resonance (NMR) is one of the most powerful methods to study the chemistry of nanomaterials, but it is currently underutilized with PSi due to low signal-to-noise ratios achieved with this material which lead to very long measurement times. Here we show that endogenous radicals exist in thermally carbonized PSi and demonstrate the feasibility of solid-state dynamic nuclear polarization (DNP) NMR without addition of organic radicals. Use of DNP NMR is demonstrated to highly improve the signal-to-noise ratio while significantly reducing the measurement times. This technique opens new possibilities for the use of more advanced NMR techniques allowing the detailed characterization of complex materials such as PSi. Furthermore, the chemical structure of thermally carbonized PSi is studied by complementary techniques, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, and Raman spectroscopy.