I made gold nanorods based on this recipe;
seed solution: 7.5ml (0.2M) CTAB, 2.5ml (0.001M) HAuCl4.3H2O, and 0.6ml (0.01M) ice-cold NaBH4.
growth solution: 5ml (0.2M) CTAB, 5ml (0.001M) HAuCl4.3H2O, varying (0.004M) AgNO3 (0.11, 0.15 and 0.21ml), 0.07ml (0.778M) Ascorbic acid, and 0.01ml seed solution (after 3 hr preperation).
Can anyone tell me, why my spectra are like this? and Is there something wrong with my experiment?
In my opinion, the longitudinal peak should be shifted to right-hand side by adding more AgNO3.
Mr. Sapermsap,
are the 3 spectra from the same stock solution, only with different concentration?
-> If not, may be you get different types of nano rods , which have different spactra.
-> If, may be aggregation?
Do you use a double beam spectrometer?
Do you use a reference sample? (Pure solvent?)
For all there spectra the same cuvette?
There are two absorbance peak as shown in the graph........one is around 640nm and other one is around 550nm. As you increase the concentration of AgNO3 there is increase in peak around 550nm compare to peak around 640 nm. It may be the indication of two type of nanoparticles i.e. there is independent Au and Ag particles in your prepared sample.
Dear Nicolai
I used the same stock solution.
I used a double beam spectrometer. Each sample was put in different plastic cuvettes and I used distilled water as a reference for UV-Vis measurement.
Best Regards
Dear Bojidarka
I am not sure that my UV-Vis can achieve that wavelength but I will try to measure in that wavelength.
Best Regards
- Badges
- Science method
- Similar topics
- Methodology
- Absorption Spectroscopy
- UV-Visible Spectroscopy