Ultrafast carrier dynamics of carbon nanodots in different pH environments

Physical Chemistry Chemical Physics : PCCP
Laizhi SuiMingxing Jin

Abstract

Ultrafast carrier relaxation dynamics in fluorescent carbon nanodots is investigated by femtosecond transient absorption spectra at different pH environments so as to understand the mechanism of fluorescence for the first time. Utilizing multi-wavelength global analysis to fit the measured signal via a sequential model, four different relaxation channels are found, which are attributed to electron-electron scattering and surface state trapping, optical phonon scattering, acoustic phonon scattering and electron-hole recombination respectively. The results reveal that the surface states are mainly composed of different oxygen-containing functional groups (epoxy, carbonyl and carboxyl) and carbon atoms on the edge of the carbon backbone and can effectively trap a large number of photo-excited electrons. The deprotonation of carboxyl groups at high pH will change the distribution of π electron cloud density between the carbon backbone and surface states and consequently, compared with the excited electrons in the acidic and neutral environments, those in the alkaline environment can be more easily trapped by the surface within 1 ps, thereby giving rise to stronger fluorescence emission.

References

Jul 9, 2004·Biochimica Et Biophysica Acta·Ivo H M van StokkumRienk van Grondelle
Jun 15, 2006·Journal of the American Chemical Society·Ya-Ping SunSu-Yuan Xie
Mar 11, 2010·Advanced Materials·Goki EdaManish Chhowalla
May 13, 2010·Angewandte Chemie·Haitao LiShuit-Tong Lee
Aug 6, 2010·Angewandte Chemie·Sheila N Baker, Gary A Baker
Dec 4, 2010·Nano Letters·Mallory L MuellerLiang-Shi Li
Aug 10, 2011·Chemphyschem : a European Journal of Chemical Physics and Physical Chemistry·Sachchidanand Srivastava, Namdeo S Gajbhiye
Oct 6, 2011·Journal of the American Chemical Society·Jaehong ParkMichael J Therien
Feb 7, 2012·Chemical Communications : Chem Comm·Xin GuoSu Chen
Feb 23, 2012·Scientific Reports·Charudatta GalandePulickel M Ajayan
Mar 22, 2012·Nano Letters·Olga A DyatlovaUlrike Woggon
Mar 29, 2012·Advanced Materials·W F ZhangH Y Yang
Jul 31, 2013·Journal of the American Chemical Society·Qun ZhangYi Luo
Nov 6, 2014·Journal of the American Chemical Society·Volker StraussDirk M Guldi
May 15, 2014·The Journal of Physical Chemistry Letters·Daichi KozawaKazunari Matsuda
Jan 2, 2014·The Journal of Physical Chemistry Letters·Bharathi Konkena, Sukumaran Vasudevan
Apr 5, 2012·The Journal of Physical Chemistry Letters·Bharathi Konkena, Sukumaran Vasudevan

❮ Previous
Next ❯

Citations

Apr 6, 2017·Angewandte Chemie·Siyu LuBai Yang
Jul 18, 2017·Luminescence : the Journal of Biological and Chemical Luminescence·Pichan SaheedaSankaran Jayaleksmi
Jul 18, 2019·Physical Chemistry Chemical Physics : PCCP·Alice SciortinoFabrizio Messina
Mar 24, 2020·Nanoscale Horizons : the Home for Rapid Reports of Exceptional Significance in Nanoscience and Nanotechnolgy·Weitao LiMinghong Wu
Feb 9, 2021·Frontiers in Chemistry·Cui LiuMingzhen Zhang
Jan 16, 2021·Angewandte Chemie·Demetra S AchilleosErwin Reisner
Mar 12, 2021·The Journal of Physical Chemistry Letters·Cui LiuDai-Wen Pang
Aug 19, 2021·The Journal of Physical Chemistry Letters·Srijon GhoshAmitava Patra

❮ Previous
Next ❯

Related Concepts

Trending Feeds

COVID-19

Coronaviruses encompass a large family of viruses that cause the common cold as well as more serious diseases, such as the ongoing outbreak of coronavirus disease 2019 (COVID-19; formally known as 2019-nCoV). Coronaviruses can spread from animals to humans; symptoms include fever, cough, shortness of breath, and breathing difficulties; in more severe cases, infection can lead to death. This feed covers recent research on COVID-19.

Blastomycosis

Blastomycosis fungal infections spread through inhaling Blastomyces dermatitidis spores. Discover the latest research on blastomycosis fungal infections here.

Nuclear Pore Complex in ALS/FTD

Alterations in nucleocytoplasmic transport, controlled by the nuclear pore complex, may be involved in the pathomechanism underlying multiple neurodegenerative diseases including Amyotrophic Lateral Sclerosis and Frontotemporal Dementia. Here is the latest research on the nuclear pore complex in ALS and FTD.

Applications of Molecular Barcoding

The concept of molecular barcoding is that each original DNA or RNA molecule is attached to a unique sequence barcode. Sequence reads having different barcodes represent different original molecules, while sequence reads having the same barcode are results of PCR duplication from one original molecule. Discover the latest research on molecular barcoding here.

Chronic Fatigue Syndrome

Chronic fatigue syndrome is a disease characterized by unexplained disabling fatigue; the pathology of which is incompletely understood. Discover the latest research on chronic fatigue syndrome here.

Evolution of Pluripotency

Pluripotency refers to the ability of a cell to develop into three primary germ cell layers of the embryo. This feed focuses on the mechanisms that underlie the evolution of pluripotency. Here is the latest research.

Position Effect Variegation

Position Effect Variagation occurs when a gene is inactivated due to its positioning near heterochromatic regions within a chromosome. Discover the latest research on Position Effect Variagation here.

STING Receptor Agonists

Stimulator of IFN genes (STING) are a group of transmembrane proteins that are involved in the induction of type I interferon that is important in the innate immune response. The stimulation of STING has been an active area of research in the treatment of cancer and infectious diseases. Here is the latest research on STING receptor agonists.

Microbicide

Microbicides are products that can be applied to vaginal or rectal mucosal surfaces with the goal of preventing, or at least significantly reducing, the transmission of sexually transmitted infections. Here is the latest research on microbicides.

© 2022 Meta ULC. All rights reserved