Separating graphene quantum dots by lateral size through gel column chromatography

Abstract

GQDs prepared through a photo-Fenton reaction were separated into eight groups with different sizes and fluorescent colors via gel column chromatography.

Graphene Quantum Dots Band Structure Tuned by Size for Efficient Organic Solar Cells

“…The UV–Vis absorption spectra shape become steeper and steeper from GQDs‐orange to GQDs‐blue. The fluorescence quantum yields (QYs) of GQDs‐orange, GQDs‐green, and GQDs‐blue are 0.758%, 5.905%, and 0.259%, respectively, as described in our previous work …”

“…The dialysis bag of 100–500 Da (retained molecular weight) was used for the purification of as‐prepared GQDs. Different sizes of GQDs were separated from the as‐prepared GQDs with the method of Sephadex G‐25 gel column chromatography as described in our previous work . Briefly, 4 mL of the as‐prepared GQDs aqueous suspension with a concentration of 2 mg mL −1 was added into the top of Sephadex G‐25 gel column.…”

Insights into Fluorophores of Dual-Emissive Carbon Dots Derived by Naphthalenediol Solvothermal Synthesis

“…However, this giant solvatochromism is hardly observed in the C-dot solution (Figure 7c,d). Figure 7e,f summarizes the PL peak position and QY as a function of E T (30), an indicator of solvent polarity. 57 With an increase of E T (30), the peak position of ECNO redshifts greatly but that of the C-dot solution shows no significant change.…”

“…Although carbon dots (C-dots) have found wide applications in various fields ranging from energy conversion to bioanalytics, − their complex structures and insufficient purification have frequently led to misleading conclusions in reported studies. − Increasing research studies have revealed that the photoluminescence (PL) of C-dots obtained from bottom-up routes is associated with versatile emission species: fluorophores, supramolecules or molecular aggregates, polymers, quasi-carbon dots, confined graphene fragments, and carbogenic nanoparticles. ,,− These species can be roughly divided into two categories: molecular fluorophores that are akin to organic dyes − and carbogenic nanodots bearing crystalline or amorphous phase of carbon. , In recent years, many types of molecular fluorophores have been separated and identified as single fluorescence origins inside carbon dots, − such as citrazinic acid, 2-pyridine compounds, , pyrrolo­[3,4- c ]­pyridine, methylenesuccinic acid, thiazolo­[3,2- a ]­pyridine, etc. Compared with its carbogenic counterpart, the fluorophore-dominated fluorescence is frequently characterized as possessing excitation independence, high fluorescence quantum yield (QY), single fluorescence lifetime, and environmental sensitivity. , …”

“…12,13,15−20 These species can be roughly divided into two categories: molecular fluorophores that are akin to organic dyes 21−23 and carbogenic nanodots bearing crystalline or amorphous phase of carbon. 16,17 In recent years, many types of molecular fluorophores have been separated and identified as single fluorescence origins inside carbon dots, 24−26 such as citrazinic acid, 27 2-pyridine compounds, 28,29 pyrrolo [3,4-c]pyridine, 30 methylenesuccinic acid, 24 thiazolo[3,2-a]pyridine, 31 etc. Compared with its carbogenic counterpart, the fluorophore-dominated fluorescence is frequently characterized as possessing excitation independence, high fluorescence quantum yield (QY), single fluorescence lifetime, and environmental sensitivity.…”