DOI: 10.1016/j.watres.2018.11.084
Scopus记录号: 2-s2.0-85058636239
论文题名: Visible-light-driven photocatalytic degradation of diclofenac by carbon quantum dots modified porous g-C 3 N 4 : Mechanisms, degradation pathway and DFT calculation
作者: Liu W. ; Li Y. ; Liu F. ; Jiang W. ; Zhang D. ; Liang J.
刊名: Water Research
ISSN: 431354
出版年: 2019
起始页码: 8
结束页码: 19
语种: 英语
英文关键词: Carbon nitride
; Carbon quantum dots
; Diclofenac
; Photocatalytic degradation
; Visible light
Scopus关键词: Chemical bonds
; Degradation
; Density functional theory
; Light
; Molecules
; Nanocrystals
; Nitrides
; Organic pollutants
; Photocatalysis
; Porous materials
; Reusability
; Semiconductor quantum dots
; Water pollution
; Carbon quantum dots
; Diclofenac
; Photo catalytic degradation
; Photocatalytic activities
; Photoexcited electrons
; Photogenerated electrons
; Porous graphitic carbon
; Visible light
; Carbon nitride
; carbon nanoparticle
; carbon quantum dot
; diclofenac
; graphitic carbon nitride
; quantum dot
; superoxide
; unclassified drug
; carbon
; catalysis
; catalyst
; chemical compound
; degradation
; photodegradation
; pollutant removal
; polymerization
; quantum mechanics
; visible spectrum
; Article
; chemical bond
; chemical structure
; degradation kinetics
; density functional theory
; electron transport
; light
; nanofabrication
; photocatalysis
; photodegradation
; polymerization
; priority journal
; radical reaction
英文摘要: Metal-free photocatalysts have attracted growing concern in recent years. In this work, a new class of carbon quantum dots (CQDs) modified porous graphitic carbon nitride (g-C 3 N 4 ) is synthesized via a facile polymerization method. With the optimal CQDs loading, the CQDs modified g-C 3 N 4 exhibits ∼15 times higher degradation kinetic towards diclofenac (DCF) than that of pure g-C 3 N 4 . The enhanced photocatalytic activity can be ascribed to the improved separation of charge carriers as well as the tuned band structure. Moreover, a photosensitation-like mechanism is proposed to elucidate the photo-generated electrons transfer and reactive radicals formation. CQDs are anchored to g-C 3 N 4 surface via C–O bond, which provide channels for the preferential transfer of photo-excited electrons on DCF molecule to the conduction band of g-C 3 N 4 . Superoxide radical (·O 2 − ) dominates the degradation of DCF, while holes (h + ) show a negligible contribution. Density functional theory (DFT) calculation successfully predicts that the sites on DCF molecule with high Fukui index (f 0 ) are preferable to be attacked by radicals. DCF degradation pathway mainly includes ring hydroxylation, ring closure and C–N bond cleavage processes. Acute toxicity estimation indicates the formation of less toxic intermediates/products compared to DCF after photocatalysis. Moreover, the hybrid photocatalysts exhibit good reusability in five consecutive cycles. This work not only proposes a deep insight into photosensitation-like mechanism in the photocatalysis system by using C 3 N 4 -based materials, but also develops new photocatalysts for potential application on removal of emerging organic pollutants from waters and wastewaters. © 2018 Elsevier Ltd
Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/122073
Appears in Collections: 气候变化事实与影响
There are no files associated with this item.
作者单位: Key Laboratory of Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing, 400045, China; The Key Laboratory of Water and Sediment Sciences, Ministry of Education, College of Environmental Sciences and Engineering, Peking UniversityBeijing 100871, China; The Beijing Innovation Center for Engineering Science and Advanced Technology (BIC-ESAT), Peking UniversityBeijing 100871, China
Recommended Citation:
Liu W.,Li Y.,Liu F.,et al. Visible-light-driven photocatalytic degradation of diclofenac by carbon quantum dots modified porous g-C 3 N 4 : Mechanisms, degradation pathway and DFT calculation[J]. Water Research,2019-01-01