The optical properties of top-down synthesized oxidized graphene quantum dots (ox-GQDs) and nitrogen-incorporating graphene quantum dots (N-GQDs) along a range of hydrothermal treatment temperatures were observed. By controlling the hydrothermal treatment temperature, different chemical states of nitrogen atoms were incorporated into GQDs. Below 150 °C, edge-terminating amines and amides dominated the nitrogen content of N-GQDs. Above 150 °C, nitrogen was primarily present in the forms of pyridinic, pyrrolic and quaternary N. In addition to the absorbance and emission profiles of ox-GQDs and N-GQDs, pH-dependent emission spectra were collected to probe chemical states of nitrogen atoms and investigate the relationship between nitrogen location and photoluminescence.
|Number of pages||5|
|State||Published - 2017|
Bibliographical noteFunding Information:
The authors thank Prof. Ambrose Seo and John Connell for AFM characterization. The authors appreciate Dali Qian for TEM characterizations. This work was supported by the National Science Foundation under Cooperative Agreement No. 1355438. The purchase of a new XPS system recently installed at the University of Kentucky was supported by the fund from the NSF EPSCoR grant (grant no. 0814194).
© 2017 The Royal Society of Chemistry.
ASJC Scopus subject areas
- Chemistry (all)
- Chemical Engineering (all)