The effect of pH was investigated at three different conditions including
acidic, neutral and basic forms. Fig. 5 shows the UV–vis spectra
of silver nanoparticles at pH = 3.0, 5.0, 7.0 and 9.0, respectively. The
result shows that the synthesis of silver nanoparticles completed at a
neutral condition andwith an increase in pHcan not showany upheaval
in UV–vis spectra for silver nanoparticles. On the other hand, in the
acidic condition we cannot observe any absorbance band for silver
nanoparticles. The aggregation of silver nanoparticles to form larger
nanoparticles was believed to be favored over the nucleation. In
addition, the Fig. 3 inset shows the changing silver nanoparticle color
at a different temperature that confirms UV–vis spectra in