CHEM01200604009 Sreejith Kaniyankandy - Homi Bhabha ...

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and intensity show absence of other TiO 2 phases like brookite and rutile. From the XRD
pattern we can conclude that the anatase phase is the only phase present with absence of
amorphous phase. The peaks are also broadened clearly indicating nm domain size of
particles.
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Intensity (a.u)
60
50
40
30
20
B-TiO 2
T-TiO 2
10 (101)
(004) (200) (211)
Bulk Anatase
0
20 30 40 50 60
2 (Degrees)
Figure 3.2. XRD patterns of TiO 2 samples
3.3.2. Steady State UV-Vis Absorption Studies
To study interfacial ET dynamics it is very important to monitor optical absorption
spectroscopy of dye molecules in presence of nanoparticles. Figure 3.3 shows the optical
absorption spectra of the dye in toluene (3.3b) and on TiO 2 (3.3c). It is clearly observed from
the figure that the absorption peak appears in toluene at ~421 nm. However, in presence of
TiO 2 particles the absorption peak broadened considerably towards the red side.