24
T. B. Asafa et al.
(b)
(a)
(c)
438.5 nm
419 nm
Fig. 3 UV-vis absorption spectra for a AgNPs biosynthesized using cocoa bean extract (Azeez
et al. 2017), b AgNPs biosynthesized using Bacillus safensis cell-free extract (Lateef et al. 2015),
c ZnO nanoparticles (Pudukudy and Yaakob 2015)
peaks at wavelength 438.5 and 419 nm for AgNPs biosynthesized using cocoa bean
extract and B. safensis extract, respectively, which is a signature of surface plasmonic resonance properties of AgNPs. For ZnO nanoparticles powder dispersed in
distilled water, the UV-vis spectrum (Fig. 3c) showed peak characteristics of hexagonal wurtzite ZnO nanoparticles at 378 nm indicating infrared shift compared to
that of bulk ZnO with its calculated energy band of 3.38 eV (Pudukudy and Yaakob
2015). The absorption spectral of different mono-metallic and bimetallic nanoparticles varies widely, and these are determined through UV-vis measurement. The
transformation in the color formation during the reduction metal ions to zerovalent forms causes the absorption of UV-vis light, which signifies the formation of
nanoparticles.
1.2 Fourier Transform Infrared Spectroscopy
Fourier transform infrared spectroscopy (FTIR) is an analytical technique that
depends on the principle of infrared spectroscopy, and it has been employed to study
various nanomaterials. It is a technique of data measurement whereby spectra are
T. B. Asafa et al.
(b)
(a)
(c)
438.5 nm
419 nm
Fig. 3 UV-vis absorption spectra for a AgNPs biosynthesized using cocoa bean extract (Azeez
et al. 2017), b AgNPs biosynthesized using Bacillus safensis cell-free extract (Lateef et al. 2015),
c ZnO nanoparticles (Pudukudy and Yaakob 2015)
peaks at wavelength 438.5 and 419 nm for AgNPs biosynthesized using cocoa bean
extract and B. safensis extract, respectively, which is a signature of surface plasmonic resonance properties of AgNPs. For ZnO nanoparticles powder dispersed in
distilled water, the UV-vis spectrum (Fig. 3c) showed peak characteristics of hexagonal wurtzite ZnO nanoparticles at 378 nm indicating infrared shift compared to
that of bulk ZnO with its calculated energy band of 3.38 eV (Pudukudy and Yaakob
2015). The absorption spectral of different mono-metallic and bimetallic nanoparticles varies widely, and these are determined through UV-vis measurement. The
transformation in the color formation during the reduction metal ions to zerovalent forms causes the absorption of UV-vis light, which signifies the formation of
nanoparticles.
1.2 Fourier Transform Infrared Spectroscopy
Fourier transform infrared spectroscopy (FTIR) is an analytical technique that
depends on the principle of infrared spectroscopy, and it has been employed to study
various nanomaterials. It is a technique of data measurement whereby spectra are