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Indexed by:Journal Papers

Date of Publication:2021-07-21

Journal:DIAMOND AND RELATED MATERIALS

Volume:87

Page Number:233-241

ISSN No.:0925-9635

Key Words:Graphene quantum dots; Gaseous detonation; Formation mechanism; Photoluminescence mechanism

Abstract:Graphene quantum dots (GQDs) in high reproducibility are synthesized by a gaseous detonation method which converts untreated benzoic acid (BA) precursor into powdered GODs without complicated post-treatment in 3-5 ms. The as-prepared GQDs resulting in an absolute photoluminescence quantum yield (PLQY) of 21.5% exhibit dual-wavelength-independent emission with the maximum PL emission at 431 nm and 460 rim under excitation maximum at 300 nm dispersed in ethyl alcohol. Based on surface structure, photoluminescence (PL) behaviors of GQDs and the characteristics of gaseous detonation, the formation mechanism of GQDs is speculated. Moreover, further study regarding the optical properties of reducing GQDs (R-GQDs) and thermal annealing GQDs (A-GQDs), it is possible to reveal PL mechanism of GQDs. This research not only provides a onepot solvent-free route to rapid and large-scale preparation of GQDs, but also accounts for the hypothetic formation and PL mechanism of the obtained GQDs.