Figure 4.

(a) Reaction sequences of in situ reaction of naringin with 0.25 mM of aqueous AgNO₃, at pH = 2.5, 7, and 11.5. Bottles “A”, “B”, and “C” show the Ag NP solutions prepared, respectively. No reaction occurs at pH 2.5. Solution “C” can be extracted into the organic phase, and (b) its corresponding UV–visible spectra with different concentrations of naringin. Panels (c,d) show the TEM images of self-crystallized naringin along with entrapped Au NPs prepared at pH 7, while (e,f) images of monodispersed Ag NPs prepared by using its chalcone at pH 11.5. Inset of (f) depicts the XRD patterns of Ag NPs. See details in text.