was ascribed to the higher adsorptivity of the MB dye, excellent electrical properties
of graphene, increased charge separation efficiency, more π–π interactions between
the composite and the pollutants, as well as the large surface contact between
La-TiO 2 nanoparticles and graphene. The particle size, graphene contents, and
targeted pollutants for the different graphene/semiconductor composites are
presented in Table 1.2.
Table 1.2 Graphene and semiconductor composites for photocatalytic degradation of pollutants
Graphene composites
Particle
size (nm)
Graphene
contents
(wt.%)
Pollutants
References
TiO 2 /graphene
10–30
3
MB
Kim et al.
(2012)
TiO 2 /graphene
5–40
1
2,4dichlorophenoxyacetic
acid and reactive red 195
Ghasemi et al.
(2013)
TiO 2 /graphene
–
1–10
MO
Khalid et al.
(2013a)
TiO 2 /graphene
10–15
10.8
RhB
Lei et al. (2012)
TiO 2 /graphene
5 nm pore
diameter
1
RhB and norfloxacin
Li et al. (2012)
TiO 2 /graphene
20–200
–
MB
Pan et al. (2012)
TiO 2 /graphene
12.3–41.0 –
Butane
Štengl et al.
(2011)
TiO 2 /graphene
18
–
RhB
Wang et al.
(2011b)
ZnO/Ag/graphene
$200
RhB
Xu et al.
(2013a)
CdSe/graphene/TiO 2
–
34.22
MO and RhB
Ghosh et al.
(2013a)
ZnO/graphene
20
–
MB and MO
Ahmad et al.
(2013b)
ZnO/graphene
6
–
MB
Fu et al. (2013)
Graphene/ZnO
$10
–
RhB
Saravanakumar
et al. (2013)
Graphene/Ag-ZnO
32
10
MB, RhB and MO
Ahmad et al.
(2013a)
CdSe/graphene
$10
54.08
MO and RhB
Ghosh et al.
(2013b)
PbS-graphene/TiO 2
$15–19
for TiO 2
–
MB
Ullah et al.
(2014)
$20–25
for PbS
ZnFe 2 O 4 /graphene
5
–
RhB, MO and MB
Lu et al. (2013)
(continued)
20
F. Opoku et al.