Production of yellow-emitting carbon quantum dots from fullerene carbon soot

Abstract

Carbon quantum dots (CQDs) have emerged as a new generation of photoluminescent nanomaterials with wide applications. Among the various synthetic routes for CQDs, the acid-refluxing method, which belongs to the group of "top-down" methods, offers the advantage of large-scale production of CQDs and uses cheap and abundantly available starting materials. In this study, we evaluated the potential of fullerene carbon soot (FCS), a by-product obtained during the synthesis of fullerene, as the starting material for CQD production. It was found that FCS can be successfully converted to CQDs in high production yield in mixed acids, i.e., concentrated HNO3 and H2SO4, under mild conditions. The fluorescence quantum yield (Φ) of the as-produced CQDs is in the range of 3%-5%, which is the highest value for CQDs obtained from "top-down" methods. Importantly, the CQDs prepared by this method show emission in the yellow range of the visible light, which is advantageous for their various potential applications. Further investigations reveal that the CQDs are highly photostable over a wide pH range and show good resistance against ionic strength and long-term UV irradiation. This further expands their potential use under harsh conditions.

A Mini Review on Carbon Quantum Dots: Preparation, Properties, and Electrocatalytic Application

“…Acid oxidation treatment have been widely used to exfoliate and decompose bulk carbon into nanoparticles, and simultaneously introduce hydrophilic groups, e.g., hydroxyl group or carboxyl group on the surface thereof to obtain CQDs (Shen and Xia, 2014; Zhang et al, 2017b), which could significantly improve the water solubility and fluorescence characteristics. In 2014, Yang et al (2014) reported a large-scale synthesis of heteroatom-doped CQDs via acid oxidation, followed by hydrothermal reduction.…”

“…The variation of particle size and PL emission can be reflected from the broad and excitation-dependent PL emission spectrum (Sun et al, 2006). Zhang et al (2017b) studied the emission behaviors of CQDs under an irradiation at 470 nm wavelength with various concentrations. It was found that the PL strength of the CQDs solution first increased and then decreased as the concentration increased.…”

Carbon and graphene quantum dots: a review on syntheses, characterization, biological and sensing applications for neurotransmitter determination

“…Moreover, other examinations revealed that the CQDs have been strongly photostable in the broad pH-range and showed appropriate resistance in the ionic strength and lengthy UV irradiation which in turn increases their usage potential in undesirable conditions. 42 2.1.2. Bottom-up methods 2.1.2.1.…”

Polyethylene Glycol6000/carbon Nanodots as Fluorescent Bioimaging Agents

“…The PL emission changes due to particle size can be reflected in a broad excitation-dependent PL emission spectrum [24]. By studying the emission behavior of CQD at various concentrations at 470 nm, Zhang et al [25] reported that an increase in the concentration of the CQD solution led to an initial increase followed by a decrease in its PL intensity.…”