conduction band of Cu 2 O (À0.7 eV) to conduction band of g-C 3 N 4 (À1.13 eV).
Successful formation of p–n heterojunction leads to efficient separation of electrons
and holes and 95% degradation of methyl orange dye within 60 min.
Exploiting inherent properties of TiO 2 semiconductor, Min et al. (2017) synthesized universal TiO 2 /g-C 3 N 4 /Cu 2 O photocatalyst for 98.5% discoloration of RhB
dye within 3 min and 100% removal of methylene blue and methyl orange dyes
within 10 min of visible light irradiation. The homogenous distribution of TiO 2 and
Cu 2 O on the surface of g-C 3 N 4 was established by transmission electron microscopy
and scanning electron microscope/energy dispersive using X-ray analysis as
displayed in Fig. 2.11.
Sudrajat (2017) performed abatement of atrazine via g-C 3 N 4 /Cu 2 O photocatalyst.
Anchoring of Cu 2 O and valence state of Cu
+2 are estimated via X-ray photoelectron
spectroscopy as demonstrated in Fig. 2.12 of 0.8% Cu 2 O loading on g-C 3 N 4 . As
shown in Fig. 2.12a, two symmetric prominent peaks at 932 and 952 eV confirm
existence of Cu in +1 oxidation state. The characteristic peak at 284 eV is attributed
to sp
2 -hybridized carbon in C–N–C lattice system of g-C 3 N 4 in Fig. 2.12b. A weak
additional peak as shown in Fig. 2.12c disappeared on loading of Cu, and this is
assigned to the presence of amino group and tertiary N-atom. The diminishing of
peak was attributed to association of Cu
+1 with amino moieties of g-C 3 N 4 .
Bao and Chen (2017) studied Z-scheme mechanism-assisted Cu 2 O/Cu/g-C 3 N 4
photocatalyst and observed that Cu
o acts as charge separation unit as the fermi level
of Cu is lower than conduction band of g-C 3 N 4 . Hence, e
À from conduction band of
g-C 3 N 4 migrates into metallic Cu to decrease recombination rate of electron–hole
pair. The main reactive species involved in degradation of phenol and MO dye are
hydroxyl and superoxide radicals detected using 5,5 dimethyl-1-pyrollidine-N-oxide
on the basis of electron spin radical trapping experiment. Similar work was carried
out for elimination of methyl orange and methylene blue dyes from simulated water
(Yan et al. 2017). Studies have revealed microbial disinfection activity of g-C 3 N 4 /
Fig. 2.10 Mechanistic illustration of g-C 3 N 4 /Cu 2 O photocatalyst under visible light irradiation (a)
before contact and (b) after contact with formation of internal electric field (IEF). (Reprinted with
permission from Tian et al. in (2014) copyright@2014 Elsevier Inc. All rights reserved)
68
P. Raizada et al.
Successful formation of p–n heterojunction leads to efficient separation of electrons
and holes and 95% degradation of methyl orange dye within 60 min.
Exploiting inherent properties of TiO 2 semiconductor, Min et al. (2017) synthesized universal TiO 2 /g-C 3 N 4 /Cu 2 O photocatalyst for 98.5% discoloration of RhB
dye within 3 min and 100% removal of methylene blue and methyl orange dyes
within 10 min of visible light irradiation. The homogenous distribution of TiO 2 and
Cu 2 O on the surface of g-C 3 N 4 was established by transmission electron microscopy
and scanning electron microscope/energy dispersive using X-ray analysis as
displayed in Fig. 2.11.
Sudrajat (2017) performed abatement of atrazine via g-C 3 N 4 /Cu 2 O photocatalyst.
Anchoring of Cu 2 O and valence state of Cu
+2 are estimated via X-ray photoelectron
spectroscopy as demonstrated in Fig. 2.12 of 0.8% Cu 2 O loading on g-C 3 N 4 . As
shown in Fig. 2.12a, two symmetric prominent peaks at 932 and 952 eV confirm
existence of Cu in +1 oxidation state. The characteristic peak at 284 eV is attributed
to sp
2 -hybridized carbon in C–N–C lattice system of g-C 3 N 4 in Fig. 2.12b. A weak
additional peak as shown in Fig. 2.12c disappeared on loading of Cu, and this is
assigned to the presence of amino group and tertiary N-atom. The diminishing of
peak was attributed to association of Cu
+1 with amino moieties of g-C 3 N 4 .
Bao and Chen (2017) studied Z-scheme mechanism-assisted Cu 2 O/Cu/g-C 3 N 4
photocatalyst and observed that Cu
o acts as charge separation unit as the fermi level
of Cu is lower than conduction band of g-C 3 N 4 . Hence, e
À from conduction band of
g-C 3 N 4 migrates into metallic Cu to decrease recombination rate of electron–hole
pair. The main reactive species involved in degradation of phenol and MO dye are
hydroxyl and superoxide radicals detected using 5,5 dimethyl-1-pyrollidine-N-oxide
on the basis of electron spin radical trapping experiment. Similar work was carried
out for elimination of methyl orange and methylene blue dyes from simulated water
(Yan et al. 2017). Studies have revealed microbial disinfection activity of g-C 3 N 4 /
Fig. 2.10 Mechanistic illustration of g-C 3 N 4 /Cu 2 O photocatalyst under visible light irradiation (a)
before contact and (b) after contact with formation of internal electric field (IEF). (Reprinted with
permission from Tian et al. in (2014) copyright@2014 Elsevier Inc. All rights reserved)
68
P. Raizada et al.