Recent Advances on Synthesis and Potential Applications of Carbon Quantum Dots

Abstract

Fluorescent carbon nanoparticles also termed as carbon quantum dots (CQDs) have attracted so much interest when compared to the traditional semiconductor quantum dots due to their applications in chemical sensing, biomedical imaging, nanotechnology, photovoltaics, light-emitting diodes (LEDs), and electrochemistry. Along with their optical features, CQDs have desired properties such as less toxicity, environmentally friendly nature, inexpensive, and simple preparation processes. In addition, CQDs can have their physical and chemical properties controlled by surface passivation and functionalization. This article provides an account of CQDs because of their distinct characteristics and considerable capacity in diverse applications. The article is categorized into various sections that highlight various synthesis methodologies of CQDs with their advantages/disadvantages and their potential applications in sensors, bio-imaging, drug delivery, solar cells, and supercapacitors. The different applications of CQDs can be demonstrated by controlled synthesis methods. We have also discussed gas sensing applications of CQDs briefly and provided a brief overview of osmotic power generation using CQDs for energy applications.

Biogenic Synthesis of Fluorescent Carbon Dots (CDs) and Their Application in Bioimaging of Agricultural Crops

“…A simple and facile one-pot synthesis of the fluorescent CDs from orange waste peels was performed using the hydrothermal carbonization method at a mild temperature (180 °C). Likewise, in the present study, the biogenic synthesis of the CDs in the aqueous system results in a lesser yield, as mentioned in the results Section 3.1 , i.e., 83 mg per 1 g equating to nearly 8%, however, is more economical than other organic solvents like PEG (polyethylene glycol) used in the synthesis of CDs reported earlier in several studies [ 23 , 32 , 35 , 61 , 68 ]. The QY analysis demonstrated a lesser QY, that might be an attribute of larger CDs and a broad size distribution.…”

“…Carbon Dots (CDs) offer a great potential for a broad range of applications such as energy-saving, bioimaging, biosensors, lasers, and light-emitting diodes [ 4 , 35 , 63 , 64 ]. They may also be applied as a promising new type of fluorescence marker as well as a high-efficiency catalyst design for applications in bioscience and energy technology [ 4 , 65 , 66 ].…”

“…These tiny CDs have recently attracted wide attention globally because of their strong fluorescence, for which they are referred to as fluorescent CDs [ 32 ]. CDs are a novel class of zero-dimensional nanoparticles with sizes below 10 nm [ 33 , 34 , 35 ], first obtained during the purification of single-walled carbon nanotubes (SWCNTs) through electrophoresis in 2004. CDs have gradually become the center of attraction in the carbon family, due to their benign, abundant, and inexpensive nature and their unique properties that reveal a strong fluorescence.…”

Fabrication of High‐Performance MgCoO2/PEDOT:PSS@Nickel Foam Anode for Bioelectricity Generation by Microbial Fuel Cells

“…Since anode materials have significant role in MFCs, there are numerous studies on the development, modification, and designing of the anode materials in order to subside the challenges in the construction and operation of MFCs [6][7][8][9]. The most common materials used in the construction of anode involve carbon-based materials [10,11], metal/metal oxides, and conducting polymers [12]. However, in the case of conventional materials starting from carbon-based materials such as carbon paper, fibers, sheets, and rods; graphite-based sheets, brushes, fibers, and cloth; metal/metal oxide-based materials involving Fe, Ag, Au, Al, Cu, Co, and CuO; and other conducting polymers such as polyaniline and polypyrrole have been found not efficient in MFCs [6,13,14].…”

Research Progress in the Synthesis of Carbon Dots and Their Application in Food Analysis

“…Since the discovery of CDs, there has been continuous research for more efficient synthetic paths to further improve the optical properties of CDs and expand their applications, which are mainly divided into two techniques: top-down and bottom-up [ 24 , 25 , 26 , 27 ].…”