among [Bi 2 O 2 ]
2+ layers. The composites exhibit efficient photocatalytic
performance, and nearly 94% and 61% of methyl blue and phenol were degraded
within 2 h.
Wang et al. (2017) successfully loaded nitrogen-doped carbon dots onto the
surface of g-C 3 N 4 composites via polymerized method to design nitrogen-doped
carbon dots/g-C 3 N 4 photocatalysts. Graphitic carbon nitride is a visible light active
metal-free photocatalyst with a band gap of 2.7 eV with various applications in CO 2
reduction, H 2 production, and pollutant degradation. The photocatalytic activity of
nitrogen-doped carbon dots/g-C 3 N 4 was remarkably higher as compared to g-C 3 N 4
and was assessed against indomethacin under visible light. Novel carbon quantum
dots/g-C 3 N 4 metal-free nanocomposites were synthesized via electrostatic selfassembly method, facile low temperature process, and impregnation-thermal method
(Jian et al. 2016; Hong et al. 2016; Zhang et al. 2016). Carbon quantum dots/g-C 3 N 4
exhibits excellent electron transfer properties, and its photocatalytic activity was
assessed against methyl blue, tetracycline hydrochloride, rhodamine B, and phenol
under visible light. By using electrostatic self-assembly method, the size, composition, porosity, and surface functionality can be easily modified. An effective
harvesting of solar light due to up-conversion process by carbon quantum dots is
one of the reasons why carbon quantum dots/g-C 3 N 4 is highly efficient.
Hu et al. (2019) synthesize mesoporous nitrogen-doped carbon quantum
dot/BiOCl composites via solvothermal reduction method. The composites exhibit
excellent photocatalytic activity against organic pollutant under visible region and
near-infrared light. The photodegradation process is mainly dependent on holes and
superoxide radical. Qu et al. (2019) fabricated graphene oxide/carbon dot/BiOI
ternary nanocomposites by using simple one-step solvothermal method. The ternary
nanocomposites exhibit excellent photocatalytic activity against the
photodegradation of 4-chlorophenol in the visible region. The synergistic effect of
nonmetallic graphene oxide, carbon nanodots, and BiOI is responsible for high
efficiency. The photodegradation efficiency decreases in the order graphene oxide/
carbon dot/BiOI> carbon dot/BiOI> graphene oxide/BiOI> BiOI, respectively, in
3 h under visible light.
Xie et al. (2018) construct graphene oxide/g-C 3 N 4 /MoO 3 Z-scheme
photocatalysts and photocatalytic activity against tetracycline antibiotic. The high
efficiency is ascribed to the synergistic effect of Z-scheme heterojunction. Further, a
ternary composite, carbon quantum dots/CdSe/reduced graphene oxide, is fabricated
by hydrothermal method (Huo et al. (2017). The optical and electronic properties
were analyzed by transmission electron microscope, x-ray diffraction, and photoelectrochemical testing. The photocatalytic performance is investigated for the
photodegradation of tetracycline hydrochloride. Although the carbon quantum dots
have a promising application in nanotechnology and nanomedicine, a lot of work is
still needed to be explored for the designing of smart materials.
3 Metal and Carbon Quantum Dot Photocatalysts for Water Purification
105
2+ layers. The composites exhibit efficient photocatalytic
performance, and nearly 94% and 61% of methyl blue and phenol were degraded
within 2 h.
Wang et al. (2017) successfully loaded nitrogen-doped carbon dots onto the
surface of g-C 3 N 4 composites via polymerized method to design nitrogen-doped
carbon dots/g-C 3 N 4 photocatalysts. Graphitic carbon nitride is a visible light active
metal-free photocatalyst with a band gap of 2.7 eV with various applications in CO 2
reduction, H 2 production, and pollutant degradation. The photocatalytic activity of
nitrogen-doped carbon dots/g-C 3 N 4 was remarkably higher as compared to g-C 3 N 4
and was assessed against indomethacin under visible light. Novel carbon quantum
dots/g-C 3 N 4 metal-free nanocomposites were synthesized via electrostatic selfassembly method, facile low temperature process, and impregnation-thermal method
(Jian et al. 2016; Hong et al. 2016; Zhang et al. 2016). Carbon quantum dots/g-C 3 N 4
exhibits excellent electron transfer properties, and its photocatalytic activity was
assessed against methyl blue, tetracycline hydrochloride, rhodamine B, and phenol
under visible light. By using electrostatic self-assembly method, the size, composition, porosity, and surface functionality can be easily modified. An effective
harvesting of solar light due to up-conversion process by carbon quantum dots is
one of the reasons why carbon quantum dots/g-C 3 N 4 is highly efficient.
Hu et al. (2019) synthesize mesoporous nitrogen-doped carbon quantum
dot/BiOCl composites via solvothermal reduction method. The composites exhibit
excellent photocatalytic activity against organic pollutant under visible region and
near-infrared light. The photodegradation process is mainly dependent on holes and
superoxide radical. Qu et al. (2019) fabricated graphene oxide/carbon dot/BiOI
ternary nanocomposites by using simple one-step solvothermal method. The ternary
nanocomposites exhibit excellent photocatalytic activity against the
photodegradation of 4-chlorophenol in the visible region. The synergistic effect of
nonmetallic graphene oxide, carbon nanodots, and BiOI is responsible for high
efficiency. The photodegradation efficiency decreases in the order graphene oxide/
carbon dot/BiOI> carbon dot/BiOI> graphene oxide/BiOI> BiOI, respectively, in
3 h under visible light.
Xie et al. (2018) construct graphene oxide/g-C 3 N 4 /MoO 3 Z-scheme
photocatalysts and photocatalytic activity against tetracycline antibiotic. The high
efficiency is ascribed to the synergistic effect of Z-scheme heterojunction. Further, a
ternary composite, carbon quantum dots/CdSe/reduced graphene oxide, is fabricated
by hydrothermal method (Huo et al. (2017). The optical and electronic properties
were analyzed by transmission electron microscope, x-ray diffraction, and photoelectrochemical testing. The photocatalytic performance is investigated for the
photodegradation of tetracycline hydrochloride. Although the carbon quantum dots
have a promising application in nanotechnology and nanomedicine, a lot of work is
still needed to be explored for the designing of smart materials.
3 Metal and Carbon Quantum Dot Photocatalysts for Water Purification
105