Chemistry Reference
In-Depth Information
3.2.
Composites of exfoliated graphene oxide- and Co
3
O
4
or RuO
x
The XRD pattern of EGO-Co
3
O
4
is shown in Fig. 5. The diffraction
peaks of as-synthesized composites belong to characteristic peaks of
Co
3
O
4
, which are close to the reported values (JCPDS file no.43-1003)
with lattice constant of a = 8.083 Ǻ. The broad peaks of Co
3
O
4
in the
X-ray pattern indicate that the nanoparticles are small and the average
size is about 15 nm as determined using Scherrer equation. Figure 6
shows the SEM images of EGO-Co
3
O
4
and it is observed that the surface
of EGO is randomly decorated with Co
3
O
4
. The XRD pattern of
EGO-RuO
x
composite shows an amorphous ruthenium oxide phase for
the as-prepared material. Annealing the composite at 300°C makes the
material crystalline typical of rutile type structure of RuO
2
(Fig. 7).
50
(311)
40
30
(111)
(001)
20
(400)
(440)
(511)
(220)
10
0
10
20
30
40
50
60
70
2 theta(
o
)
Fig. 5. XRD pattern of EGO-Co
3
O
4
composite.
Fig. 6. SEM images of EGO-Co
3
O
4
composite. The scale bars correspond to 30 µm (left)
and 300 µm (right).
