1 / 11

Au Nanorods and Pd Nanoparticles

Au Nanorods and Pd Nanoparticles. Sriram Chandrasekhar Prof. Michael S. Wong. Department of Chemical and Biomolecular Engineering Rice University, Houston, TX. Experiments Summary. Au Nanorods Synthesis. Seed Solution CTAB: 5.0 ml, 0.20M HAuCl 4 : 5.0 ml, 0.0005M

gilda
Télécharger la présentation

Au Nanorods and Pd Nanoparticles

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Au Nanorods andPd Nanoparticles Sriram Chandrasekhar Prof. Michael S. Wong Department of Chemical and Biomolecular Engineering Rice University, Houston, TX

  2. Experiments Summary

  3. Au Nanorods Synthesis Seed Solution CTAB: 5.0 ml, 0.20M HAuCl4: 5.0 ml, 0.0005M NaBH4: 0.6 ml, 0.01M (iced) Rigorous Stirring Growth Solution CTAB: 5.0 ml, 0.20M AgNO3: [0.05-0.25] ml, 0.004M HAuCl4: 5.0 ml, 0.001M Ascorbic Acid: 70ul, 0.0788M Product Seed Solution: 12 ul Add to Growth Solution Wait 10-20 min 0.05ml AgNO3 0.10ml AgNO3 0.15ml AgNO3 0.20ml AgNO3 0.25ml AgNO3 Seed Solution Growth Solution Products after 20 mins

  4. Product Pictures 0.05ml AgNO3 0.10ml AgNO3 0.15ml AgNO3 0.20ml AgNO3 0.25ml AgNO3 0.05ml AgNO3 0.10ml AgNO3 0.15ml AgNO3 0.20ml AgNO3 0.25ml AgNO3 Products after 20 mins Products after 10 mins

  5. Au Nanorods Characterization UV-Vis Spectra of synthesized Au NRs UV-Vis Spectra of Au NRs from Paper The two spectra compare favorably with peaks at similar wavelengths indicating a successful synthesis of Au NRs of different lengths. The sample with 0.15 ml of AgNO3 did not grow to the expected length, but this is likely due to human error in preparation.

  6. 11 mL DEG 15.0 mM Na2PdCl4 458 mM KBr 67 mM PVP Pd Nanocubes Synthesis DEG = diethylene glycol Parr: oven 100 ºC, 3h Na2PdCl4 + KBr In 3ml DEG Product Expected length: 12nm (Dark Brown) PVP + 8ml DEG

  7. 11 mL solution 5.8 mM Na2PdCl4 28 mM Citric Acid 29 mM PVP Pd Icosahedra Synthesis DEG = diethylene glycol Parr: oven 90 ºC, 26h Na2PdCl4 In water Product Expected edge lengths: 25nm (Grey) Citric Acid + PVP In water

  8. Motivation for DEG NCube Synthesis • Pd Cuboctahedrathermodynamically favorable shape; 4nm edge length • Gives the highest catalytic activity among Pd-only NPs. • Cuboctahedra have 6 {100} and 8 {111} facets • Paper determines that slow reduction of Pd salt leads to Ncubes; DEG is a weak reducing agent • Result of DEG reduction in paper:NCubes with edge length: 8nmFacets: All {100} facets

  9. TCE HDC Reaction Normalized Mass Ethane/Pentane The Pd nanocubes showed better catalytic activity Rate constants were calculated using the formula: kt = ln(1/(1-X)) where X is conversion. Thus k is the slope from a plot of ln(1/(1-X)) vs. t

  10. Au@Pd Core/Shell Nbars • Au NR Synthesis: same procedure as described above • Required chemicals are available

More Related