Spektrofotometer UV-Vis Untuk Estimasi Ukuran Nanopartikel Perak
Abstract: We present a simple
technique to estimate the size of silver nanoparticles (AgNPs) based on uv-vis
spectra computationally. To have the nanoparticles, the AgNPs colloid was
prepared by chemical reduction technique using 40 mM of tri-sodium citrate
dihydrate (Na3C6H5O7.2H2O) and silver nitrate (AgNO3) at different
concentrations of 2.5 and 5.0 mM. The colloid was then analyzed by using UV-Vis
spectrophotometer. For comparison of the size estimation, a small amount of
AgNPs was also analyzed using transmission electron microscopy (TEM). By
fitting the model and the UV-Vis spectra of these colloids, the set fitting
parameters can be obtained including the absorption coefficient, the full width
at half maximum (FWHM), the wavelength and absorbance of peaks. It is assumed
that the shape of nanoparticle is spherical, so that its diameter can be
estimated using the values of scattered absorbance and FWHM. Based on the model
it is found that the size of AgNPs are (28 ± 8) nm and (15 ± 7) nm for samples
prepared with concentration of 2.5 and 5.0 mM, respectively. On the other hand,
from statistically estimation using images from TEM, it is found that the size
of AgNPs are (17 ± 4) nm and (8 ± 3) nm for samples prepared with concentration
of 2.5 and 5.0 mM, respectively. This discrepancy occurs may be due to
non-homogenous of the particles. It indicates, however, this computationally
simple method can be used as a first step to estimate size of the AgNPs colloid
prior to measurement and calculation using advanced equipments and techniques.
Penulis: Junaidi
Kode Jurnal: jpfisikadd170085
