Synthesis of Metal Nanocrystals


Au Nanobipyramids(DOI: 10.1002/adom.201400505) (another ref on BP- templated synthesis)

  1. Seeds: H2O (9.625 mL) + TSC (0.01 M, 250 uL) + HAuCl4 (0.01 M, 125 uL) + NaBH4 (0.01 M, 150 uL, ice-cold) (left for 4hrs)
  2. Growth solutions: CTBAB (0.01 M, 28.5 mL) + HAuCl4 (0.01 M, 1.2 mL) + AgNO3 (0.01 M, 60 uL) + Ascorbic Acid (0.1 M, 402 uL)
  3. Growth solution + 1.2/0.9/0.6/0.45/0.3/0.18/0.12 mL TSC seeds, incubate in 65 oC oven for 6 hrs.

Au Nanospheres (details can be found in this publication)

  1. seed 1: CTAB (0.1 M, 9.75 mL) + HAuCl4 (0.01 M, 250 uL) + (under stirring) NaBH4 (0.01 M, 600 uL, ice-cold) (keep stirring for 3 hrs)
  2. seed 2: CTAB (0.1 M, 9.75 mL) + H2O (190 mL) + HAuCl4 (0.01 M, 4 mL) +  Ascorbic Acid (0.1 M, 15 mL) + (under stirring) seed 1 (120 uL), left for 5-8 hrs
  3. polyhedron: CTAC (0.025 M, 300 mL) +seed 2 (1.5/4/9/30 mL) + Ascorbic Acid (0.1 M, 7.5 mL) + (under stirring) HAuCl4 (0.01 M, 15 mL), keep in 45 oC, 4.5 hrs. (polyhedron with diameter ~ 220/160/120/80 nm)
  4. polyhedron (220/160/120/80 nm, 300+ mL) + HAuCl4 (0.01 M, 2~3 mL) 
    Ref: Preparation of ultrasmooth, highly spherical monocrystalline gold particles

Au Nanorods

  1. seeds: CTAB (0.1 M, 9.75 mL) + HAuCl4 (0.01 M, 250 uL) + NaBH4 (0.01 M, 600 uL, ice-cold) (left for 2-4 hrs)
  2. Growth solutions: CTAB (0.1 M, 400 mL) + HAuCl4 (0.01 M, 20 mL) + AgNO3 (0.01 M, 4 mL) +HCl (5M, 2 g)+ Ascorbic Acid (0.1 M, 3.2 mL)
  3. Growth solution + 100 uL/900 uL/10 mL seeds (for NR-40/20/10), left overnight.
    Ref:

Overgrowth of Au Nanorods

  1. adjust the pH of the Au NR solution to 2.9-3.1, using HCl/NaOH
  2. add Glutathione (GSH, 0.01 M, 20 uL) into the Au NR solution (2 mL) to make the concentration of GSH to be 100 uM
  3. left at room temperature for 2 hrs
  4. add different volume of growth solution (6,8,10,12,15 mL) into the above solution, left at room temperature for 5-6 hrs
  5. Growth solution: CTAB (0.1 M, 42.75 mL) + HAuCl4 (0.01 M, 1.8 mL) + AgNO3 (0.01 M, 270 uL) + Ascorbic Acid (0.1 M, 288 uL)

Au Nanorods@mPEG-SH

  1. Au NRs (as grown, 10 mL): wash once and disperse in H2O (10 mL)
  2. +mPEG-SH (MW = 5000, Rapp Polymere GmbH, [CH3O-PEG-SH]1 mL, 1 mM for the polymer); (1 mM = 0.05 g mPEG-SH in 10 g H2O)
  3. left in room temperature, undisturbed, for overnight
  4. wash once and disperse in H2O or ethanol (can be dispersed in various types of polar organic solvents, including ethanol,methanol,acetone, acetonitrile, DMF, DMSO and PBS)

Au Nanorods@mSiO2

  1. Au NRs (as grown, 20 mL, pH adjusted to 7~8): wash once and disperse in H2O (10 mL), +NaOH to adjust pH to ~9
  2. keep stirring at 45 degree C, add 60 uL 20% (volume %) TEOS in ethanol 3 times at a time interval of 90 min
  3. keep stirring at 45 degree C for another 2 hrs.
  4.  wash once and disperse in DI H2O (pH~4, do not need to add acids) or ethanol

Au Nanorods@SiO2

  1. 7.5 mL Au NRs@mPEG-SH (obtained from 40 mL as grown Au NRs acqueous solution) ethanol solution
  2. +2.25 mL DI H2O
  3. +150 uL 30% NH3H2O
  4. +40 uL 20% (volume %) TEOS in ethanol, room temperature keep stirring or in ultrasonic bath for 90 min. (shell coated~4 nm)
  5. repeat (4) for 3 times. wash once and disperse in DI H2O (pH~4, do not need to add acids) or ethanol

Au Nanorods@Ag

  1. Au NRs (as grown, 1 mL): wash once and disperse in CTAC (80 mM, 1 mL)
  2. +AgNO3 (0.01 M, 100 uL) +Ascorbic Acid (0.1 M, 50 uL)
  3. left in 65 oC oven

Au Nanorods@Pd (discontinuous)

  1. seed: Au NRs (as grown, 1 mL): wash once and disperse in deionized water (1 mL)
  2. Growth solution: H2O (3 mL)+CTAC (25w%, 30 uL)+H2PdCl4 (0.01 M, X uL (X=20~100))+Ascorbic Acid (0.1M, 0.5X uL)
  3. add the seed solution into the growth solution and left at room temperature for 6 hrs.

Au Nanorods@Pd (continuous) (publication)

  1. seed: Au NRs (as grown, 1 mL): wash once and disperse in deionized water (1 mL)
  2. Growth solution: H2O (2 mL)+CTAB (0.1M, 1 mL)+H2PdCl4 (0.01 M, X uL (X=20~100))+Ascorbic Acid (0.1M, 0.5X uL)
  3. add the seed solution into the growth solution and left at room temperature for 8 hrs.

Au Nanorods@Pt

  1. seed: Au NRs (as grown, 1 mL): wash once and disperse in deionized water (1 mL)
  2. Growth solution: H2O (2 mL)+CTAB (0.1 M, 1 mL)+H2PtCl4 (0.03943 M, X uL (X=10~100))+Ascorbic Acid (0.1M, 2X uL)
  3. add the seed solution into the growth solution and left  in 65 oC oven for 8 hrs.

Au Nanocrystals@TiO2 (ref)

  1. Wrapping Au nanocrystals with PSS (MW 70000, Sigma 527483):
    • Wash 10 mL as-grown nanocrystal sample stabilized with CTAB/CTAC by centrifugation to remove the excess surfactant; redisperse the nanocrystals into water (10 mL).
    • Glass flask: 10 mL H2O + 60 uL PSS (MW70000;30 wt%) = 2 g/L PSS solution
    • (under vigorous stirring) add the metal nanocrystal solution (10 mL) dropwise to the PSS solution (2 g/L, 10 mL)
    • PSS adsorption was allowed for at least 4 h at room temperature. After the excess PSS was removed by centrifugation (washed 2 times), the PSS-encapsulated metal nanocrystals were redispersed into water (200 uL).
  2. Growth of TiO2 shell
    • Glass flask: 6 mL H2O + 300 uL TiCl3 (Sigma 14010, 12% in HCl, free HCl 5-10%)
    • (under stirring) Drop Na2CO3 (1 M, 500 uL), right after that + Au NC@PSS
    • Keep stirring for 30 min
    • Wash 2 times, redisperse in 10 mL water
    • Wrapping Au nanorod with PAA/PAH

ref: https://onlinelibrary.wiley.com/doi/full/10.1002/smll.200801546

Porous Au nanocrystals:

http://pubs.acs.org/doi/abs/10.1021/jz402795x

Micrometer Au plates/Au nanoplates:

  1. http://www.sciencedirect.com/science/article/pii/S0927775705009234
  2. http://www.nature.com/ncomms/journal/v1/n9/full/ncomms1143.html (modified from ref 1)
  3. http://pubs.acs.org/doi/abs/10.1021/jp311470t (2013)
  4. http://arxiv.org/abs/1507.01387 (2015, >20 um plates)
  5. Gold nanoplates with tunable size/thickness

cross sections VS coefficients:

Calculate the absorption/scattering/extinction cross sections of nanocrystals from their absorption/scattering/extinction coefficient, which can be measured and calculated from the Beer's Law.


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