Controlled Nitrogen Doping of Graphene Quantum Dots through Laser Ablation in Aqueous Solutions for Photoluminescence and Electrocatalytic Applications

Rosemary L. Calabro, Dong Sheng Yang, Doo Young Kim

Research output: Contribution to journalArticlepeer-review

48 Scopus citations

Abstract

Nitrogen-doped graphene quantum dots (N-GQDs) have promising applications in catalysis and photoluminescence, but many existing synthetic methods require uses of harsh chemicals, long reaction times, and complicated purification steps and have poor control over the surface functional groups. Laser ablation in liquid (LAL) is a promising alternative method to prepare nanomaterials because of its fast production, use of fewer chemicals, simple purification, and fewer byproducts and its control of the product by precise tuning of laser ablation parameters. We report the use of LAL to produce N-GQDs from carbon nano-onions in aqueous solutions of ammonia, ethylenediamine, and pyridine. The choice of these dopants allowed for tuning the overall nitrogen content and the distribution of functional groups that led to the control over the photoluminescence emission wavelengths and lifetimes. High concentrations of amine groups tended to red-shift emission and exhibit shorter lifetimes, whereas pyridinic groups would blue-shift the emission and exhibit longer lifetimes. The N-GQDs also showed a promising performance as electrocatalysts for reducing oxygen to hydrogen peroxide, an important chemical widely used in industrial applications. The N-GQDs exhibited both low overpotentials and high selectivity for a two-electron oxygen reduction pathway.

Original languageEnglish
Pages (from-to)6948-6959
Number of pages12
JournalACS Applied Nano Materials
Volume2
Issue number11
DOIs
StatePublished - Nov 22 2019

Bibliographical note

Publisher Copyright:
© 2019 American Chemical Society.

Keywords

  • electrocatalysis
  • graphene quantum dots
  • laser ablation in liquid
  • lifetime
  • oxygen reduction reaction
  • photoluminescence

ASJC Scopus subject areas

  • Materials Science (all)

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