34
T. B. Asafa et al.
Fig. 13 Raman spectra of the pure and Mg-TiO 2 hollow spheres at lower Raman shift between
a 100 and 800 cm −1 , b 100 and 220 cm −1 (Gao et al. 2017)
Smith and Dent 2005). Raman analysis is a powerful technique that is sensitive to
the second phases and clusters of heterogeneous materials in matrix.
Figure 13 shows Raman spectra of pure anatase TiO 2 and Mg-doped TiO 2 samples.
The characteristic bands common to anatase TiO 2 are observed at 144 (E g ), 399 (B 1g ),
516 (A 1g + B 1g ), and 639 cm
−1 (E g ) bands (Gao et al. 2017). It is observed that the
Raman bands for all the Mg–TiO 2 are almost at the same position as observed in pure
anatase TiO 2 , and there are no others bands existed in the Raman spectra of Mg–
TiO 2 hollow sphere. But the broadening and small shift of Raman bands observed
in Fig. 13(b) indicated that the Mg ions in the Mg–TiO 2 samples are homogenously
substituted Ti in TiO 2 lattice.
1.7 Dynamic Light Scattering
Dynamic light scattering (DLS) is a technique widely deployed to characterize
nanoparticles-in-dispersion that enable monitoring of dispersion effects such as effect
of salt or pH on colloidal stability, impact of thermal or chemical stresses on protein
denaturation, or size and distribution of nanoparticles (Bauer et al. 2016; Kaszuba
et al. 2008; Moore et al. 2015). DLS is a non-invasive technique that requires comparatively low quantity of samples and provides reliable estimates of the quality of
preparation rapidly. DLS has been applied to study protein RNA, homogeneity of
proteins, and their complexes (Stetefeld et al. 2016). DLS measures diffusion of particles moving under Brownian motion and converts this to size and a size distribution
using Stokes–Einstein relationship. In principle, when laser light from a DLS equipment passes through macromolecules, the incident light scatters in all directions,
and scattering intensity is recorded by a detector. The monochromatic incident light
undergoes Doppler broadening as the macromolecules are in continuous motion in
T. B. Asafa et al.
Fig. 13 Raman spectra of the pure and Mg-TiO 2 hollow spheres at lower Raman shift between
a 100 and 800 cm −1 , b 100 and 220 cm −1 (Gao et al. 2017)
Smith and Dent 2005). Raman analysis is a powerful technique that is sensitive to
the second phases and clusters of heterogeneous materials in matrix.
Figure 13 shows Raman spectra of pure anatase TiO 2 and Mg-doped TiO 2 samples.
The characteristic bands common to anatase TiO 2 are observed at 144 (E g ), 399 (B 1g ),
516 (A 1g + B 1g ), and 639 cm
−1 (E g ) bands (Gao et al. 2017). It is observed that the
Raman bands for all the Mg–TiO 2 are almost at the same position as observed in pure
anatase TiO 2 , and there are no others bands existed in the Raman spectra of Mg–
TiO 2 hollow sphere. But the broadening and small shift of Raman bands observed
in Fig. 13(b) indicated that the Mg ions in the Mg–TiO 2 samples are homogenously
substituted Ti in TiO 2 lattice.
1.7 Dynamic Light Scattering
Dynamic light scattering (DLS) is a technique widely deployed to characterize
nanoparticles-in-dispersion that enable monitoring of dispersion effects such as effect
of salt or pH on colloidal stability, impact of thermal or chemical stresses on protein
denaturation, or size and distribution of nanoparticles (Bauer et al. 2016; Kaszuba
et al. 2008; Moore et al. 2015). DLS is a non-invasive technique that requires comparatively low quantity of samples and provides reliable estimates of the quality of
preparation rapidly. DLS has been applied to study protein RNA, homogeneity of
proteins, and their complexes (Stetefeld et al. 2016). DLS measures diffusion of particles moving under Brownian motion and converts this to size and a size distribution
using Stokes–Einstein relationship. In principle, when laser light from a DLS equipment passes through macromolecules, the incident light scatters in all directions,
and scattering intensity is recorded by a detector. The monochromatic incident light
undergoes Doppler broadening as the macromolecules are in continuous motion in