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Liu C, Bao L, Yang M, Zhang S, Zhou M, Tang B, Wang B, Liu Y, Zhang ZL, Zhang B, Pang DW. Surface Sensitive Photoluminescence of Carbon Nanodots: Coupling between the Carbonyl Group and π-Electron System. J Phys Chem Lett 2019; 10:3621-3629. [PMID: 31199162 DOI: 10.1021/acs.jpclett.9b01339] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
The functional groups and π-electron system of carbon dots (C-dots) were carefully controlled by several innovative chemical methods, without any changes in size, to unravel the relationship between the surface structure and photoluminescence (PL). The results of experiments and theoretical calculations reveal that the PL of C-dots is related to the surface state. The energy gap is determined by the coupling of the π-electron system and carbonyl group, and the quantum yield (QY) is dependent on the carbonyl group. The carbonyl group is the main factor increasing the ratio of nonradiation to radiation recombination, thereby leading to the low QY of C-dots. This work provides a strategy for effectively tuning the structure of C-dots, giving rise to the tunable PL emission wavelength and highly desirable QY, which enables us to further unravel the PL mechanism.
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Affiliation(s)
- Cui Liu
- Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), College of Chemistry and Molecular Sciences, State Key Laboratory of Virology, The Institute for Advanced Studies, and Wuhan Institute of Biotechnology , Wuhan University , Wuhan 430072 , P. R. China
- Key Laboratory of Optoelectronic Technology & Systems (Ministry of Education), Centre for Intelligent Sensing Technology, College of Optoelectronic Engineering , Chongqing University , Chongqing 400044 , P. R. China
| | - Lei Bao
- Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), College of Chemistry and Molecular Sciences, State Key Laboratory of Virology, The Institute for Advanced Studies, and Wuhan Institute of Biotechnology , Wuhan University , Wuhan 430072 , P. R. China
| | - Mengli Yang
- Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), College of Chemistry and Molecular Sciences, State Key Laboratory of Virology, The Institute for Advanced Studies, and Wuhan Institute of Biotechnology , Wuhan University , Wuhan 430072 , P. R. China
| | - Song Zhang
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics , Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences , Wuhan 430071 , P. R. China
- University of Chinese Academy of Sciences , Beijing 100049 , P. R. China
| | - Miaomiao Zhou
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics , Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences , Wuhan 430071 , P. R. China
- University of Chinese Academy of Sciences , Beijing 100049 , P. R. China
| | - Bo Tang
- Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), College of Chemistry and Molecular Sciences, State Key Laboratory of Virology, The Institute for Advanced Studies, and Wuhan Institute of Biotechnology , Wuhan University , Wuhan 430072 , P. R. China
| | - Baoshan Wang
- Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), College of Chemistry and Molecular Sciences, State Key Laboratory of Virology, The Institute for Advanced Studies, and Wuhan Institute of Biotechnology , Wuhan University , Wuhan 430072 , P. R. China
| | - Yufei Liu
- Key Laboratory of Optoelectronic Technology & Systems (Ministry of Education), Centre for Intelligent Sensing Technology, College of Optoelectronic Engineering , Chongqing University , Chongqing 400044 , P. R. China
| | - Zhi-Ling Zhang
- Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), College of Chemistry and Molecular Sciences, State Key Laboratory of Virology, The Institute for Advanced Studies, and Wuhan Institute of Biotechnology , Wuhan University , Wuhan 430072 , P. R. China
| | - Bing Zhang
- State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics , Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences , Wuhan 430071 , P. R. China
- University of Chinese Academy of Sciences , Beijing 100049 , P. R. China
| | - Dai-Wen Pang
- Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), College of Chemistry and Molecular Sciences, State Key Laboratory of Virology, The Institute for Advanced Studies, and Wuhan Institute of Biotechnology , Wuhan University , Wuhan 430072 , P. R. China
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Machado CE, Tartuci LG, de Fátima Gorgulho H, de Oliveira LFC, Bettini J, Pereira dos Santos D, Ferrari JL, Schiavon MA. Influence of Inert and Oxidizing Atmospheres on the Physical and Optical Properties of Luminescent Carbon Dots Prepared through Pyrolysis of a Model Molecule. Chemistry 2016; 22:4556-63. [PMID: 26845751 DOI: 10.1002/chem.201504234] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Indexed: 11/05/2022]
Abstract
This work used L-tartaric acid as a model molecule to evaluate how the use of inert and oxidizing atmospheres during pyrolysis affected the physical and optical properties of the resulting carbon dots (CDs). Pyrolysis revealed to be a simple procedure that afforded CDs in a single step, dismissed the addition of organic solvents, and involved only one extraction stage that employed water. By X-ray diffraction a dependency between the structure of the CDs and the atmosphere (oxidizing or inert) used during the pyrolysis was found. Potentiometric titration demonstrated that the CDs were largely soluble in water; it also aided characterization of the various groups that contained sp(3) -hybridized carbon atoms on the surface of the dots. Raman spectroscopy suggested that different amounts of sp(2)- and sp(3)-hybridized carbon atoms emerged on the CDs depending on the pyrolysis atmosphere. In conclusion, the pyrolysis atmosphere influenced the physical properties, such as the composition and the final structure.
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Affiliation(s)
- Cláudia Emanuele Machado
- Grupo de Pesquisa em Química de Materiais, GPQM, DCNat-Departamento de Ciências Naturais, Universidade Federal de São João del-Rei, UFSJ, Campus Dom Bosco, Praça Dom Helvécio, 74, CEP, 36301-160, São João del-Rei, MG, Brazil
| | - Letícia Gazola Tartuci
- Grupo de Pesquisa em Química de Materiais, GPQM, DCNat-Departamento de Ciências Naturais, Universidade Federal de São João del-Rei, UFSJ, Campus Dom Bosco, Praça Dom Helvécio, 74, CEP, 36301-160, São João del-Rei, MG, Brazil
| | - Honória de Fátima Gorgulho
- Grupo de Pesquisa em Química de Materiais, GPQM, DCNat-Departamento de Ciências Naturais, Universidade Federal de São João del-Rei, UFSJ, Campus Dom Bosco, Praça Dom Helvécio, 74, CEP, 36301-160, São João del-Rei, MG, Brazil
| | - Luiz Fernando Cappa de Oliveira
- Núcleo de Espectroscopia e Estrutura Molecular, Departamento de Química, Universidade Federal de Juiz de Fora, CEP, 36036-330, Juiz de Fora, MG, Brazil
| | - Jefferson Bettini
- Laboratório Nacional de Nanotecnologia, Centro Nacional de Pesquisa em Energia e Materiais, CEP, 13083-970, Campinas, SP, Brazil
| | - Daniela Pereira dos Santos
- Grupo de Pesquisa em Química de Materiais, GPQM, DCNat-Departamento de Ciências Naturais, Universidade Federal de São João del-Rei, UFSJ, Campus Dom Bosco, Praça Dom Helvécio, 74, CEP, 36301-160, São João del-Rei, MG, Brazil
| | - Jefferson Luis Ferrari
- Grupo de Pesquisa em Química de Materiais, GPQM, DCNat-Departamento de Ciências Naturais, Universidade Federal de São João del-Rei, UFSJ, Campus Dom Bosco, Praça Dom Helvécio, 74, CEP, 36301-160, São João del-Rei, MG, Brazil
| | - Marco Antônio Schiavon
- Grupo de Pesquisa em Química de Materiais, GPQM, DCNat-Departamento de Ciências Naturais, Universidade Federal de São João del-Rei, UFSJ, Campus Dom Bosco, Praça Dom Helvécio, 74, CEP, 36301-160, São João del-Rei, MG, Brazil.
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Feng T, Hoagland DA, Russell TP. Assembly of acid-functionalized single-walled carbon nanotubes at oil/water interfaces. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2014; 30:1072-1079. [PMID: 24443769 DOI: 10.1021/la404543s] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The efficient segregation of water-soluble, acid-functionalized, single-walled carbon nanotubes (SWCNTs) at the oil/water interface was induced by dissolving low-molecular-weight amine-terminated polystyrene (PS-NH2) in the oil phase. Salt-bridge interactions between carboxylic acid groups of SWCNTs and amine groups of PS drove the assembly of SWCNTs at the interface, monitored by pendant drop tensiometry and laser scanning confocal microscopy. The impact of PS end-group functionality, PS and SWCNT concentrations, and the degree of SWCNT acid modification on the interfacial activity was assessed, and a sharp drop in interfacial tension was observed above a critical SWCNT concentration. Interfacial tensions were low enough to support stable oil/water emulsions. Further experiments, including potentiometric titrations and the replacement of SWCNTs by other carboxyl-containing species, demonstrated that the interfacial tension drop reflects the loss of SWCNT charge as the pH falls near/below the intrinsic carboxyl dissociation constant; species lacking multivalent carboxylic acid groups are inactive. The trapped SWCNTs appear to be neither ordered nor oriented.
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Affiliation(s)
- Tao Feng
- Department of Polymer Science and Engineering, University of Massachusetts-Amherst , Amherst, Massachusetts 01003, United States
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