All-Carbon Nanosized Hybrid Materials: Fluorescent Carbon Dots Conjugated to Multiwalled Carbon Nanotubes

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• 作者：Theodosis Skaltsas ; Anastasios Stergiou ; Demetrios D. Chronopoulos ; Sihan Zhao ; Hisanori Shinohara ; Nikos Tagmatarchis
• 刊名：Journal of Physical Chemistry C
• 出版年：2016
• 出版时间：April 28, 2016
• 年：2016
• 卷：120
• 期：16
• 页码：8550-8558
• 全文大小：592K
• 年卷期：0
• ISSN：1932-7455

文摘

Fluorescent carbon dots (CDs) were synthesized by following a hydrothermal route in which butane-1,4-diamine and maleic acid were employed in a Teflon autoclave reactor. The structure and morphology of the so-formed spherically shaped CDs were confirmed by a combination of spectroscopic and imaging techniques, such as NMR, ATR-IR, DLS, XRD, and HR-TEM. Additionally, it was found that raw CDs possess numerous −NH₂ functionalities located in their external periphery, responsible for their enhanced aqueous solubility as well as the excellent dissolution CDs showed in polar protic solvents. Moreover, these −NH₂ units were utilized for covalently associating CDs with oxidized multiwalled carbon nanotubes (MWCNTs) yielding robust CDs–MWCNTs hybrids. Based on photoluminescence spectroscopy, electronic communications between the individual components of CDs–MWCNTs were evidenced by the quantitative quenching of the emission of CDs in the presence of MWCNTs as well as the shortening of the photoluminescence lifetime of CDs from 7.3 ns for raw CDs to 300 ps for CDs–MWCNTs. Finally, the redox properties of CDs–MWCNTs were evaluated by electrochemistry measurements, allowing to determine the electrochemical band gap of the hybrid material to be 1.2 eV.