Water hyacinth derived carbon quantum dots and g-C3N4 composites for sunlight driven photodegradation of 2,4-dichlorophenol

• Published in: SN applied sciences Vol. 2; no. 6; p. 1030
• Main Authors: Hak, Chen Hong, Leong, Kah Hon, Chin, Yik Heng, Saravanan, Pichiah, Tan, Sin Tee, Chong, Woon Chan, Sim, Lan Ching
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 01-06-2020; Springer Nature B.V
• Subjects: 2,4-Dichlorophenol; Application; Applied and Technical Physics; Aquatic plants; Aqueous solutions; Carbon; Carbon nitride; Carrier lifetime; Characterization; Chemistry/Food Science; Chemistry: Polymer; Composite materials; Current carriers; Earth Sciences; Efficiency; Electromagnetic absorption; Engineering; Environment; Floating plants; Hydrocarbons; Hydrothermal treatment; Irradiation; Light irradiation; Materials Science; Nanocomposites: Synthesis; Performance degradation; Photocatalysis; Photodegradation; Pollutants; Quantum dots; Research Article; Ultraviolet radiation; Water hyacinths; Zeolite; Water hyacinth; Carbon quantum dots; 2,4-Dichlorophenol; CDs/g-C; composite; N
• DOI: 10.1007/s42452-020-2840-y
• EISSN: 2523-3971
• ISSN: 2523-3963

Carbon dots (CDs) were successfully derived from water hyacinth leaves and the binary composite was achieved by incorporating CDs with g-C
3
N
4
through hydrothermal treatment. The average particle size of CDs was found to be 3.1 nm and a blue-green fluorescence was emitted under the UV light irradiation. Both of the composites loaded with 20 wt.% (20CDs/g-C
3
N
4
) and 40 wt.% (40CDs/g-C
3
N
4
) of CDs achieved the highest degradation efficiency of 2,4-dichlorophenol (2,4-DCP) with 1.7 times higher than that of pure g-C
3
N
4
. This work successfully improved the properties of g-C
3
N
4
by elongating the lifetime of photogenerated electrons and widening the visible light response. Both of 20CDs/g-C
3
N
4
and 40CDs/g-C
3
N
4
recorded the highest photocatalytic performance in degrading 2,4-DCP with degradation rate constant of 0.0194, and 0.0186 min
−1
, respectively. This is contributed by the prolonged charge carrier lifetime in 20CDs/g-C
3
N
4
; good visible light absorption and high specific surface area in 40CDs/g-C
3
N
4
. For the scavenger test, hole (h
+
) and superoxide radical (
·
O
2
−
) were acknowledged as the key active species in photocatalysis.