Nitrogen-Doped Graphene Quantum Dots with Oxygen-Rich Functional Groups

Abstract

Graphene quantum dots (GQDs) represent a new class of quantum dots with unique properties. Doping GQDs with heteroatoms provides an attractive means of effectively tuning their intrinsic properties and exploiting new phenomena for advanced device applications. Herein we report a simple electrochemical approach to luminescent and electrocatalytically active nitrogen-doped GQDs (N-GQDs) with oxygen-rich functional groups. Unlike their N-free counterparts, the newly produced N-GQDs with a N/C atomic ratio of ca. 4.3% emit blue luminescence and possess an electrocatalytic activity comparable to that of a commercially available Pt/C catalyst for the oxygen reduction reaction (ORR) in an alkaline medium. In addition to their use as metal-free ORR catalysts in fuel cells, the superior luminescence characteristic of N-GQDs allows them to be used for biomedical imaging and other optoelectronic applications.

Full‐Color Emission Polymer Carbon Dots with Quench‐Resistant Solid‐State Fluorescence

“…Polymer carbon dots (PCDs), a new type of fluorescent carbon dots (CDs), prepared through polymerization and crosslinking between small molecules, have emerged and attracted increasing interest due to their unique structures and excellent properties including low toxicity, excitation‐dependent luminescence, low cost, chemical inertness, and excellent biocompatibility 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19. The “core–shell” structure of PCDs distinguishes them from other small molecules and carbon based fluorophores by small molecule/polymer crosslinking into the emission center and holding outer polymer chains synchronously 3, 4, 6.…”

One-Step Microwave-Assisted Green Synthesis of Luminescent N-Doped Carbon Dots from Sesame Seeds for Selective Sensing of Fe(III)

“…C.dots akin to Q.dots show several interesting properties such as excitation-dependent emission, chemical and photostability, enhanced fluorescence quantum yields and the possibility of fine-tuning the sensing properties by surface modification [5][6][7][8][9][10][11] In order to improve the photophysical and photochemical properties of C.dots, hetero-atom doped C.dots are synthesized by different ways. Among them, nitrogendoped C.dots received much attention because of their good biocompatibility and the related broad applications in the areas of bio-imaging, electrocatalysis and sensors 25,26 . However, most of the synthesis methods reported so far have either a long reaction time or a need of extra chemicals for doping.…”

“…Among them, nitrogendoped C.dots received much attention because of their good biocompatibility and the related broad applications in the areas of bio-imaging, electrocatalysis and sensors 25,26 . However, most of the synthesis methods reported so far have either a long reaction time or a need of extra chemicals for doping.…”

A facile strategy for ultrasmall Pt NPs being partially-embedded in N-doped carbon nanosheet structure for efficient electrocatalysis

“…4c, the C 1s in CpPy-NS@500 can be deconvoluted to four types of peaks centered at ca. 284.8, 286.0, 288.2 and 291.7 eV, which can be assigned to C=C, C-N, C=O, and π-π * , respectively [27][28][29][30]. In Fig.…”