Fig. 2 shows the XRD patterns of the original GO, the RGO, the TiO2
nanoparticles and the RGO–TiO2 with different contents of RGO.
Fig. 2(a) illustrates that the GO had only one peak at around 10° 2θ.
After reduction, the peak was widened and moved to around 25° RGO spectrum). The shift of peak suggested that the GO had been partly
reduced to graphene: the RGO had smaller interlayer spacing than the
GO because the oxygen-containing groups were partially removed
[22]. Fig. 2(b) shows that the peaks from the RGO–TiO2 are originated
from the anatase and rutile TiO2 phases, and the relative content of anatase
and rutile phase is about 4:1, which are in excellent agreement
with that of TiO2. There is no obvious peak change at various contents
of RGO–TiO2, indicating that the TiO2 nanoparticlesmaintain their crystal
lattice structure of TiO2 after going through the reduction process.
The content of RGO is too little to be detected by XRD.