Green Chemistry-type One-Step Synthesis of Silver Nanostructures Based on MoVMoVI Mixed Valence Polyoxometalates Guangjin Zhang1, Bineta Keita1, Anne Dolbecq2, Pierre Mialane2, Francis Sécheresse2, Frédéric Miserque3, Louis Nadjo*1 1
Laboratoire de Chimie Physique, Groupe d’Electrochimie et de Photoélectrochime, UMR 8000, CNRS, Université Paris-Sud, Bâtiment 350, 91405 Orsay Cedex, France 2 Institut Lavoisier, UMR 8180, Université de Versailles St Quentin 45, avenue des Etats-Unis, 78035 Versailles Cedex, France 3 Laboratoire de Réactivité des Surfaces et Interfaces/ CEA-Saclay DEN/DANS/DPC/SCP, Bât 391, 91191 Gif-sur-Yvette Cedex
SUPPORTING INFORMATION Figure 1 SI Deconvolution of the silver core 3d levels XPS spectrum Figure 2 SI TEM image of the nanoparticles got from reaction mixture of 2, the aging time was 2h Figure 3 SI. TEM image of the nanoparticles/nanowires got from reaction mixture of 2, the aging time was 4h Figure 4 SI. Large scale TEM image of nanowires got from a replication of the reaction mixture of 2 after 4h aging. Figure 5 SI TEM image of one nanowire after washing several times with water Experimental conditions for XPS Characterisation of Ag nanoparticles
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Figure 1 SI Deconvolution of the silver core 3d levels XPS spectrum.
13600
Agmetal 3d5/2
13400 13200 13000
Counts / s
12800 12600 12400 12200 12000 11800 11600 11400 376
375
374
373
372
371
370
Binding Energy (eV)
2
369
368
367
366
365
Figure 2 SI TEM image of the nanoparticles got from reaction mixture of 2, the aging time was 2h
Figure 3 SI. TEM image of the nanoparticles/nanowires got from reaction mixture of 2, the aging time was 4h
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Figure 4 SI. Large scale TEM image of nanowires got from a replication of the reaction mixture of 2 after 4h aging.
Figure 5 SI TEM image of one nanowire after washing several times with water
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Experimental conditions for XPS Characterisation of Ag nanoparticles The samples for XPS (X-ray Photoelectron Spectroscopy) analysis were deposited on glassy carbon wafers as supports. The XPS spectrometer was a Thermo Electron ESCALAB 220i XL. The monochromatic X-ray Al K source was used for excitation, with an incident energy of 1486.6 eV. The X-ray power was 200 W (20 mA x 10 kV). The pass energy was 20 eV for detail spectra. The analysis zone was roughly (1 x 1) cm2. The monochromatic source was selected because it is better resolved in energy compared to the non-monochromatic one and is thus more suitable in case elements in large concentrations are to be determined. Among the possibilities of the XPS technique, attention was focused on the extraction of oxidation states of elements from the treatment and recombining of complex photoelectric peaks. Silver nanoparticle samples were centrifugated at 5,000 cpm for 20 min, redispersed in water, and then washed two more times with water, centrifugated after each water addition and finally redispersed in water. A drop of such solution is then deposited on a glassy carbon wafer and let to dry in a continuously argon-flushed box. Exactly the same treatment was applied to silver nanowires, except that the centrifugation speed was 2,000 cpm instead of 5,000 cpm.
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