162
M. Parthiban and G. Devanand
4 Results and Discussion
4.1 Sample Preparation
Graphene oxide (GO) was synthesized by chemical exfoliation of graphite powder
following modified Hummers’ method. 400 mg GO was first added in 100 mL
methanol and ultrasonicated for 1 h. Later, 2 g Titanium-Di-oxide was added to
the GO suspension and stirred for an hour. The obtained homogeneous suspension
was then transferred to a Teflon-lined autoclave and subjected to solvothermal treatment at 393 K for 8 h. The resultant composite was filtered, washed repeatedly with
distilled water and dried in vacuum at 333 K. The sample prepared by this procedure
is denoted as RGOT.
4.2 Characterization of RGOT Catalyst
Fourier transform infrared (FT-IR) spectra were recorded using Shimadzu DR-8101A
spectrometer in transmittance mode after making a pellet with IR grade KBr. The
powder X-ray diffractograms (XRD) were recorded using an analytical X’Pert Pro
X-ray diffractometer with Cu Kα source with a wavelength of 1.54 Å operating at
20 mA and 50 kV. The morphology of the catalysts was evaluated by JOEL 2010
F transmission electron microscope (TEM) equipped with ED and SAED operating
at 200 kV. The band gap measurements were carried out using UV–visible DRS
spectrophotometer (Jasco V650 model).
4.2.1 FTIR
GO powder presented different bands arising from oxidized groups. The band around
1720 cm
−1 is attributed to stretching vibrations from C=O of –COOH groups. The
peak at 1620 cm
−1 is due to C=C from unoxidized sp
2 bonds. The band at 1220 cm
−1
can be assigned to C–OH stretching vibrations, and the band around 1050 cm
−1
corresponds to C–O stretching vibrations. The FT-IR spectra of Titanium-Di-oxide
showed a broad band below 700 cm
−1 which is attributed to the Ti–O–Ti stretching
and bending vibrational modes and another broad band at around 3400 cm
−1 , which
is due to the O–H stretching frequency from the surface hydroxyl group. All the characteristic peaks of GO and Titanium-Di-oxide are present in the RGOT composite.
These results imply that Titanium-Di-oxide can be susceptible to the interaction
with the functional groups of RGO in the nano-composite. When GO was reduced to
RGO, all the peaks arising from oxygen containing functionality were substantially
reduced, indicating a reduction of the oxygen content in the sample. Figure 7 shows
the FT-IR spectra of graphite, GO, Titanium-Di-oxide and RGOT nano-composite.
M. Parthiban and G. Devanand
4 Results and Discussion
4.1 Sample Preparation
Graphene oxide (GO) was synthesized by chemical exfoliation of graphite powder
following modified Hummers’ method. 400 mg GO was first added in 100 mL
methanol and ultrasonicated for 1 h. Later, 2 g Titanium-Di-oxide was added to
the GO suspension and stirred for an hour. The obtained homogeneous suspension
was then transferred to a Teflon-lined autoclave and subjected to solvothermal treatment at 393 K for 8 h. The resultant composite was filtered, washed repeatedly with
distilled water and dried in vacuum at 333 K. The sample prepared by this procedure
is denoted as RGOT.
4.2 Characterization of RGOT Catalyst
Fourier transform infrared (FT-IR) spectra were recorded using Shimadzu DR-8101A
spectrometer in transmittance mode after making a pellet with IR grade KBr. The
powder X-ray diffractograms (XRD) were recorded using an analytical X’Pert Pro
X-ray diffractometer with Cu Kα source with a wavelength of 1.54 Å operating at
20 mA and 50 kV. The morphology of the catalysts was evaluated by JOEL 2010
F transmission electron microscope (TEM) equipped with ED and SAED operating
at 200 kV. The band gap measurements were carried out using UV–visible DRS
spectrophotometer (Jasco V650 model).
4.2.1 FTIR
GO powder presented different bands arising from oxidized groups. The band around
1720 cm
−1 is attributed to stretching vibrations from C=O of –COOH groups. The
peak at 1620 cm
−1 is due to C=C from unoxidized sp
2 bonds. The band at 1220 cm
−1
can be assigned to C–OH stretching vibrations, and the band around 1050 cm
−1
corresponds to C–O stretching vibrations. The FT-IR spectra of Titanium-Di-oxide
showed a broad band below 700 cm
−1 which is attributed to the Ti–O–Ti stretching
and bending vibrational modes and another broad band at around 3400 cm
−1 , which
is due to the O–H stretching frequency from the surface hydroxyl group. All the characteristic peaks of GO and Titanium-Di-oxide are present in the RGOT composite.
These results imply that Titanium-Di-oxide can be susceptible to the interaction
with the functional groups of RGO in the nano-composite. When GO was reduced to
RGO, all the peaks arising from oxygen containing functionality were substantially
reduced, indicating a reduction of the oxygen content in the sample. Figure 7 shows
the FT-IR spectra of graphite, GO, Titanium-Di-oxide and RGOT nano-composite.