Spectroscopic Characteristics of Carbon Dots (C-Dots) Derived from Carbon Fibers and Conversion to Sulfur-Bridged C-Dots Nanosheets
Abstract
We synthesized sub‐10 nm carbon nanoparticles (CNPs) consistent with photoluminescent carbon dots (C-dots) from carbon fiber starting material. The production of different C-dots fractions was monitored over seven days. During the course of the reaction, one fraction of C-dots species with relatively high photoluminescence was short-lived, emerging during the first hour of reaction but disappearing after one day of reaction. Isolation of this species during the first hour of the reaction was crucial to obtaining higher-luminescent C-dots species. When the reaction proceeded for one week, the appearance of larger nanostructures was observed over time, with lateral dimensions approaching 200 nm. The experimental evidence suggests that these larger species are formed from small C-dot nanoparticles bridged together by sulfur-based moieties between the C-dot edge groups, as if the C-dots polymerized by cross-linking the edge groups through sulfur bridges. Their size can be tailored by controlling the reaction time. Our results highlight the variety of CNP products, from sub‐10 nm C-dots to ~200 nm sulfur-containing carbon nanostructures, that can be produced over time during the oxidation reaction of the graphenic starting material. Our work provides a clear understanding of when to stop the oxidation reaction during the top-down production of C-dots to obtain highly photoluminescent species or a target average particle size.
Additional Information
© 2015 Society for Applied Spectroscopy. Publication date: September 1, 2015. We acknowledge the financial support for this study by the National Science Foundation, USA: Grants CHE 1058373, CHE 1048740 (CRIFMU), CHE-0848171, and CHE-1126301. The authors thank Dr. David Watson for use of the UV-Vis and fluorescence spectrophotometers, Dr. Sarbajit Banerjee for providing access to the Raman spectrophotometer, and Dr. Joseph A. Gardella for discussions on XPS.Attached Files
Published - as-69-9-1082.pdf
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Additional details
- Eprint ID
- 61465
- Resolver ID
- CaltechAUTHORS:20151023-080949581
- CHE-1058373
- NSF
- CHE-1048740
- NSF
- CHE-0848171
- NSF
- CHE-1126301
- NSF
- Created
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2015-10-26Created from EPrint's datestamp field
- Updated
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2021-11-10Created from EPrint's last_modified field