Au Nanorods and Pd Nanoparticles Sriram Chandrasekhar Prof

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 Method: Niko obak & Seed ht. Solution El. CTAB: Saye 5. 0 ml, 0. 20 M d. HAu. Cl. Che 4: 5. 0 ml, 0. 0005 M m. Na. BHMate 4: 0. 6 ml, 0. 01 M (iced) r. , Rigorous Vol. Stirring 15, No. 10, 2003 Seed Solution Growth Solution Product CTAB: 5. 0 ml, 0. 20 M Seed Solution: 12 ul Ag. NO 3: [0. 05 -0. 25] ml, 0. 004 M Add to Growth Solution HAu. Cl 4: 5. 0 ml, 0. 001 M Wait 10 -20 min Ascorbic Acid: 70 ul, 0. 0788 M Growth Solution 0. 05 ml 0. 10 ml 0. 15 ml 0. 20 ml 0. 25 ml Ag. NO 3 Products after 20 mins

Product Pictures 0. 05 ml 0. 10 ml 0. 15 ml 0. 20 ml 0. 25 ml Ag. NO 3 Products after 10 mins 0. 05 ml 0. 10 ml 0. 15 ml 0. 20 ml 0. 25 ml Ag. NO 3 Products after 20 mins

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 Ag. NO 3 did not grow to the expected length, but this is likely due to human error in preparation.

Pd Nanocubes Synthesis Method: Xia et al; J. Am. Che m. Soc. , Vol 129, No. 12, Na 2007 Pd. Cl 2 DEG = diethylene glycol 4 Parr: oven 100 ºC, 3 h + KBr In 3 ml DEG 11 m. L DEG 15. 0 m. M Na 2 Pd. Cl 4 458 m. M KBr 67 m. M PVP + 8 ml DEG Product Expected length: 12 nm (Dark Brown)

Pd Icosahedra Synthesis Method: Xia et al; Adv. Funct. Mate r. Vol 19, pg 189200, 2009 DEG = diethylene glycol Parr: oven 90 ºC, 26 h Na 2 Pd. Cl 4 In water 11 m. L solution 5. 8 m. M Na 2 Pd. Cl 4 28 m. M Citric Acid 29 m. M PVP Product Expected edge lengths: 25 nm (Grey) Citric Acid + PVP In water

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

Normalized Mass Ethane/Pentane TCE HDC Reaction 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 k Icosahedra Nanocube 0. 0016 0. 0068

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