Catalytic Methods for the Synthesis of Carbon Nanodots and Their Applications

A special issue of Catalysts (ISSN 2073-4344). This special issue belongs to the section "Biomass Catalysis".

Deadline for manuscript submissions: closed (30 September 2023) | Viewed by 30738

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Department of Chemistry, Modern College of Arts, Science, and Commerce, Pune, India
Interests: synthesis of magnetic nanoparticles and metal or metal oxide nanoparticles anchored on graphene and carbon nanotubes for biomedical applications

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Dear Colleagues,

Carbon dots (CDs) are a new class of carbon nanomaterials with astounding properties and applications. Thanks to the innovation in the characterization of nanomaterials with high resolution, the observation of these new materials, which have gone unnoticed thus far, has become a reality. A Web of Science search with the keywords of carbon dots and sensors showed 18,424 results (on 9th August 2022), a marker of the intensity of research in this field. The growth in the number of publications on this subject during the past decade (2012-2021) is shown in Figure 1. 

Carbon dots, as the name implies, represent carbon nanomaterials of particle size less than 10 nm and with near-spherical shape. They have unusual properties, such as solubility in water, photostability, biocompatibility, environmental friendliness, sustainability of feedstock, fluorescence, photoluminescence, electrochemiluminescence, and many more. They are highly susceptible to functionalization and hybridization, resulting in multifunctionality. These materials, namely functionalized CDs, can sense almost anything, as evident from the list that follows: water, humidity, monoamine, Hg (II), Fe (III), pyrimethanil, pH, hippuric acid, H2O2, glutathione, Pb2+, Ni2+, I-, pentachlorophenol, phosphate, tetrazole, aspartic acid, glucose, Mg2+, Ca2+, pertilachlor, NH3 vapour, nitrite, bacteria, viruses, 2, 4, 6-trinitrotoluene, CN-, dopamine, ascorbic acid, organic solvents, acetic acid vapour, urea, urease, NO2, aromatic volatile organic compounds, intracellular glucose, pesticides, benzo[a]pyrene, norepinephrine, acetylcholine, aspirin, V5+, NO, colchicine, H2S, hydrazine, 2, 4-dichlorophenol, ciprofloxacin, morin, capraicin, L-Lysine, methyl parathion,, tartrazine, tetracycline, lactate, bromate, aflatoxin B1, hypochlorite, celecoxib, epinephrine, picric acid, Ag (I), levodopa, pyridoxine, glutathione, Cr6+, CO2, cholesterol ciproflaxin, duloxetine, ractopamine, lanthanide and actinide ions, 2, 6-pyridine dicarboxilic acid, organophosphorous pesticides, doxorubicin hydrocholoride, prilocaine, biothiols, K+ in serum, nitro aromatic explosives, formic acid vapour, 2, 4, 6-trinitro phenol, sulphide, glutathione, natural products (flavonoids), L-cysteine, acetone, picric acid, adrenaline, Au (III), catechol, cysteine, histidine, phosphate, bisphenol A, progesterone, F-, nifedipine, mercaptopurine, uric acid, sildenafil citrate, folic acid, sulphites, isoniazid, penicillamine, radiation, tetra bromo bisphenol, L-phenylalanine, ClO-, mesalazine, gallic acid, ampicillin, Co2+, oxytetracycline, paraquat, hemin, thiabendazole, caffeic acid, trypsin, 3-nitrotyrosine, and many more. There is no relevance in the order shown above; they were copy and pasted as they appear in the Web of Science in the interest of time. The variety and diversity of the sensing ability of these functionalized carbon materials is, thus, evident and this warrants a Special Issue on this topic in the MDPI journal Catalysts

Dr. Indra Neel Pulidindi
Dr. Archana Deokar
Prof. Dr. Aharon Gedanken
Guest Editors

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Keywords

  • carbon dots
  • carbon quantum dots
  • carbon nanodots
  • sensors
  • bioimaging
  • biomarkers
  • biocompatibility
  • biolabels
  • biosensors
  • cellular imaging

Published Papers (12 papers)

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Research

Jump to: Review

15 pages, 4377 KiB  
Article
One-Pot Synthesis of Green-Emitting Nitrogen-Doped Carbon Dots from Xylose
by Gabriela Rodríguez-Carballo, Cristina García-Sancho, Manuel Algarra, Eulogio Castro and Ramón Moreno-Tost
Catalysts 2023, 13(10), 1358; https://doi.org/10.3390/catal13101358 - 10 Oct 2023
Viewed by 1255
Abstract
Carbon dots (CDs) are interesting carbon nanomaterials that exhibit great photoluminescent features, low cytotoxicity, and excellent water stability and solubility. For these reasons, many fields are starting to integrate their use for a variety of purposes. The catalytic performance of VOPO4 has [...] Read more.
Carbon dots (CDs) are interesting carbon nanomaterials that exhibit great photoluminescent features, low cytotoxicity, and excellent water stability and solubility. For these reasons, many fields are starting to integrate their use for a variety of purposes. The catalytic performance of VOPO4 has been evaluated in the synthesis of nitrogen-doped carbon dots (N-CDs). The synthesis reaction was carried out at 180 °C using VOPO4 as a heterogeneous catalyst for 2 to 4 h of reaction time. After reaction, the N-CDs were purified using a novel method for the protection of the functional groups over the surfaces of the N-CDs. The morphological, superficial, and photoelectronic properties of the N-CDs were thoroughly studied by means of TEM, HRTEM, XPS, and photoluminescence measurements. The conversion of the carbon precursor was followed by HPLC. After three catalytic runs, the catalyst was still active while ensuring the quality of the N-CDs obtained. After the third cycle, the catalyst was regenerated, and it recovered its full activity. The obtained N-CDs showed a great degree of oxidized groups in their surfaces that translated into high photoluminescence when irradiated under different lasers. Due to the observed photoelectronic properties, they were then assayed in the photocatalytic degradation of methyl orange. Full article
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23 pages, 3164 KiB  
Article
Anodic Catalyst Support via Titanium Dioxide-Graphene Aerogel (TiO2-GA) for A Direct Methanol Fuel Cell: Response Surface Approach
by Siti Hasanah Osman, Siti Kartom Kamarudin, Sahriah Basri and Nabila A. Karim
Catalysts 2023, 13(6), 1001; https://doi.org/10.3390/catal13061001 - 14 Jun 2023
Viewed by 1130
Abstract
The direct methanol fuel cell (DMFC) has the potential for portable applications. However, it has some drawbacks that make commercialisation difficult owing to its poor kinetic oxidation efficiency and non-economic cost. To enhance the performance of direct methanol fuel cells, various aspects should [...] Read more.
The direct methanol fuel cell (DMFC) has the potential for portable applications. However, it has some drawbacks that make commercialisation difficult owing to its poor kinetic oxidation efficiency and non-economic cost. To enhance the performance of direct methanol fuel cells, various aspects should be explored, and operational parameters must be tuned. This research was carried out using an experimental setup that generated the best results to evaluate the effectiveness of these variables on electrocatalysis performance in a fuel cell system. Titanium dioxide-graphene aerogel (TiO2-GA) has not yet been applied to the electrocatalysis area for fuel cell application. As a consequence, this research is an attempt to boost the effectiveness of direct methanol fuel cell electrocatalysts by incorporating bifunctional PtRu and TiO2-GA. The response surface methodology (RSM) was used to regulate the best combination of operational parameters, which include the temperature of composite TiO2-GA, the ratio of Pt to Ru (Pt:Ru), and the PtRu catalyst composition (wt%) as factors (input) and the current density (output) as a response for the optimisation investigation. The mass activity is determined using cyclic voltammetry (CV). The best-operating conditions were determined by RSM-based performance tests at a composition temperature of 202 °C, a Pt/Ru ratio of (1.1:1), and a catalyst composition of 22%. The best response is expected to be 564.87 mA/mgPtRu. The verification test is performed, and the average current density is found to be 568.15 mA/mgPtRu. It is observed that, after optimisation, the PtRu/TiO2-GA had a 7.1 times higher current density as compared to commercial PtRu. As a result, a titanium dioxide-graphene aerogel has potential as an anode electrocatalyst in direct methanol fuel cells. Full article
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15 pages, 2729 KiB  
Article
Three-Dimensional Graphene Aerogel Supported on Efficient Anode Electrocatalyst for Methanol Electrooxidation in Acid Media
by Siti Hasanah Osman, Siti Kartom Kamarudin, Sahriah Basri and Nabilah A. Karim
Catalysts 2023, 13(5), 879; https://doi.org/10.3390/catal13050879 - 12 May 2023
Cited by 6 | Viewed by 1034
Abstract
This work attempted to improve the catalytic performance of an anodic catalyst for use in direct methanol fuel cells by coating graphene aerogel (GA) with platinum nanoparticles. A hydrothermal, freeze-drying, and microwave reduction method were used to load Pt–Ru bimetallic nanoparticles onto a [...] Read more.
This work attempted to improve the catalytic performance of an anodic catalyst for use in direct methanol fuel cells by coating graphene aerogel (GA) with platinum nanoparticles. A hydrothermal, freeze-drying, and microwave reduction method were used to load Pt–Ru bimetallic nanoparticles onto a graphene aerogel. The mesoporous structure of a graphene aerogel is expected to enhance the mass transfer in an electrode. XRD, Raman spectroscopy, SEM, and TEM described the as-synthesized PtRu/GA. Compared to commercial PtRu/C with the same loading (20%), the electrocatalytic performance of PtRu/GA presents superior stability in the methanol oxidation reaction. Furthermore, PtRu/GA offers an electrochemical surface area of 38.49 m2g−1, with a maximal mass activity/specific activity towards methanol oxidation of 219.78 mAmg−1/0.287 mAcm−2, which is higher than that of commercial PtRu/C, 73.11 mAmg−1/0.187 mAcm−2. Thus, the enhanced electrocatalytic performance of PtRu/GA for methanol oxidation proved that GA has excellent potential to improve the performance of Pt catalysts and tolerance towards CO poisoning. Full article
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18 pages, 6735 KiB  
Article
Highly Efficient Self-Assembled Activated Carbon Cloth-Templated Photocatalyst for NADH Regeneration and Photocatalytic Reduction of 4-Nitro Benzyl Alcohol
by Vaibhav Gupta, Rajesh K. Yadav, Ahmad Umar, Ahmed A. Ibrahim, Satyam Singh, Rehana Shahin, Ravindra K. Shukla, Dhanesh Tiwary, Dilip Kumar Dwivedi, Alok Kumar Singh, Atresh Kumar Singh and Sotirios Baskoutas
Catalysts 2023, 13(4), 666; https://doi.org/10.3390/catal13040666 - 29 Mar 2023
Cited by 4 | Viewed by 1450
Abstract
This manuscript emphasizes how structural assembling can facilitate the generation of solar chemicals and the synthesis of fine chemicals under solar light, which is a challenging task via a photocatalytic pathway. Solar energy utilization for pollution prevention through the reduction of organic chemicals [...] Read more.
This manuscript emphasizes how structural assembling can facilitate the generation of solar chemicals and the synthesis of fine chemicals under solar light, which is a challenging task via a photocatalytic pathway. Solar energy utilization for pollution prevention through the reduction of organic chemicals is one of the most challenging tasks. In this field, a metal-based photocatalyst is an optional technique but has some drawbacks, such as low efficiency, a toxic nature, poor yield of photocatalytic products, and it is expensive. A metal-free activated carbon cloth (ACC)–templated photocatalyst is an alternative path to minimize these drawbacks. Herein, we design the synthesis and development of a metal-free self-assembled eriochrome cyanine R (EC-R) based ACC photocatalyst (EC-R@ACC), which has a higher molar extinction coefficient and an appropriate optical band gap in the visible region. The EC-R@ACC photocatalyst functions in a highly effective manner for the photocatalytic reduction of 4-nitro benzyl alcohol (4-NBA) into 4-amino benzyl alcohol (4-ABA) with a yield of 96% in 12 h. The synthesized EC-R@ACC photocatalyst also regenerates reduced forms of nicotinamide adenine dinucleotide (NADH) cofactor with a yield of 76.9% in 2 h. The calculated turnover number (TON) of the EC-R@ACC photocatalyst for the reduction of 4-nitrobenzyl alcohol is 1.769 × 1019 molecules. The present research sets a new benchmark example in the area of organic transformation and artificial photocatalysis. Full article
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13 pages, 6342 KiB  
Article
Eco-Friendly Synthesis of Functionalized Carbon Nanodots from Cashew Nut Skin Waste for Bioimaging
by Somasundaram Chandra Kishore, Suguna Perumal, Raji Atchudan, Thomas Nesakumar Jebakumar Immanuel Edison, Ashok K. Sundramoorthy, Muthulakshmi Alagan, Sambasivam Sangaraju and Yong Rok Lee
Catalysts 2023, 13(3), 547; https://doi.org/10.3390/catal13030547 - 09 Mar 2023
Cited by 3 | Viewed by 2033
Abstract
In this study, Anacardium occidentale (A. occidentale) nut skin waste (cashew nut skin waste) was used as a raw material to synthesize functionalized carbon nanodots (F-CNDs). A. occidentale biomass-derived F-CNDs were synthesized at a low temperature (200 °C) using a facile, [...] Read more.
In this study, Anacardium occidentale (A. occidentale) nut skin waste (cashew nut skin waste) was used as a raw material to synthesize functionalized carbon nanodots (F-CNDs). A. occidentale biomass-derived F-CNDs were synthesized at a low temperature (200 °C) using a facile, economical hydrothermal method and subjected to XRD, FESEM, TEM, HRTEM, XPS, Raman Spectroscopy, ATR-FTIR, and Ultraviolet-visible (UV–vis) absorption and fluorescence spectroscopy to determine their structures, chemical compositions, and optical properties. The analysis revealed that dispersed, hydrophilic F-CNDs had a mean diameter of 2.5 nm. XPS and ATR-FTIR showed F-CNDs had a crystalline core and an amorphous surface decorated with –NH2, –COOH, and C=O. In addition, F-CNDs had a quantum yield of 15.5% and exhibited fluorescence with maximum emission at 406 nm when excited at 340 nm. Human colon cancer (HCT-116) cell assays showed that F-CNDs readily penetrated into the cells, had outstanding biocompatibility, high photostability, and minimal toxicity. An MTT assay showed that the viability of HCT-116 cells incubated for 24 h in the presence of F-CNDs (200 μg mL–1) exceeded 95%. Furthermore, when stimulated by filters of three different wavelengths (405, 488, and 555 nm) under a laser scanning confocal microscope, HCT-116 cells containing F-CNDs emitted blue, red, and green, respectively, which suggests F-CNDs might be useful in the biomedical field. Thus, we describe the production of a fluorescent nanoprobe from cashew nut waste potentially suitable for bioimaging applications. Full article
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17 pages, 3813 KiB  
Article
Unveiling the Photocatalytic Activity of Carbon Dots/g-C3N4 Nanocomposite for the O-Arylation of 2-Chloroquinoline-3-carbaldehydes
by Ravichandran Manjupriya and Selvaraj Mohana Roopan
Catalysts 2023, 13(2), 308; https://doi.org/10.3390/catal13020308 - 30 Jan 2023
Cited by 3 | Viewed by 1796
Abstract
Visible-light-active, organic, heterogeneous photocatalysts offer an ecologically friendly and sustainable alternative to traditional metal-based catalysts. In this work, we report the microwave synthesis of nanocarbon dots (CDs), loaded with graphitic carbon nitride (g-C3N4). The fabricated nanocomposite was shown to [...] Read more.
Visible-light-active, organic, heterogeneous photocatalysts offer an ecologically friendly and sustainable alternative to traditional metal-based catalysts. In this work, we report the microwave synthesis of nanocarbon dots (CDs), loaded with graphitic carbon nitride (g-C3N4). The fabricated nanocomposite was shown to exhibit various properties, such as the Schottky heterojunction. The optical properties, functional group analysis, surface morphology, crystallinity, chemical stability, electronic properties, and pore size distribution of the synthesized nanocomposite were analyzed by Ultraviolet-Diffuse Reflectance Spectroscopy (UV-DRS), Photoluminescence (PL), Fourier Transform Infrared Spectroscopy (FTIR), Transmission Electron Microscopy (TEM), X-Ray Diffraction (XRD), Zeta potential, X-Ray Photoelectron Spectroscopy (XPS), and Brunauer–Emmett–Teller (BET). Until now, to the best of our knowledge, there have been no reports published on the light-assisted synthesis of O-arylation of 2-chloroquinoline-3-carbaldehyde. Therefore, we explored the photocatalytic activity of the fabricated nanocomposite in the production of the O-arylated 2-chloroquinoline-3-carbaldehyde. This facile technique uses a blue LED light source as a non-conventional source and operates under moderate conditions, resulting in useful O-arylated products. The experimental data shows the good recyclability of the catalyst for up to five cycles without a loss in catalytic activity, a simple operational protocol, easy recoverability of the catalyst, and good product yields (65–90%) within 12–24 h. Additionally, the preliminary mechanistic investigations are discussed. The results show that the phenoxy and quinoline-3-carbaldehyde radicals generated upon blue LED irradiation during the course of the reaction are responsible for C-O bond formation, which results in O-arylation. The present study clearly indicates that 0D/2D nanocomposites have a bright future as metal-free, heterogeneous photocatalysts suitable for organic reactions. Full article
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15 pages, 8825 KiB  
Article
Highly Selective Nitrogen-Doped Graphene Quantum Dots/Eriochrome Cyanine Composite Photocatalyst for NADH Regeneration and Coupling of Benzylamine in Aerobic Condition under Solar Light
by Ruchi Singh, Rajesh K. Yadav, Ravindra K. Shukla, Satyam Singh, Atul P. Singh, Dilip K. Dwivedi, Ahmad Umar and Navneet K. Gupta
Catalysts 2023, 13(1), 199; https://doi.org/10.3390/catal13010199 - 14 Jan 2023
Cited by 4 | Viewed by 2287
Abstract
Photocatalysis is an ecofriendly and sustainable pathway for utilizing solar energy to convert organic molecules. In this context, using solar light responsive graphene-based materials for C–N bond activation and coenzyme regeneration (nicotinamide adenine dinucleotide hydrogen; NADH) is one of the utmost important and [...] Read more.
Photocatalysis is an ecofriendly and sustainable pathway for utilizing solar energy to convert organic molecules. In this context, using solar light responsive graphene-based materials for C–N bond activation and coenzyme regeneration (nicotinamide adenine dinucleotide hydrogen; NADH) is one of the utmost important and challenging tasks in this century. Herein, we report the synthesis of nitrogen-doped graphene quantum dots (NGQDs)-eriochrome cyanine (EC) solar light active highly efficient “NGQDs@EC” composite photocatalyst for the conversion of 4-chloro benzylamine into 4-chloro benzylamine, accompanied by the regeneration of NADH from NAD+, respectively. The NGQDs@EC composite photocatalyst system is utilized in a highly efficient and stereospecific solar light responsive manner, leading to the conversion of imine (98.5%) and NADH regeneration (55%) in comparison to NGQDs. The present research work highlights the improvements in the use of NGQDs@EC composite photocatalyst for stereospecific NADH regeneration and conversion of imine under solar light. Full article
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14 pages, 5133 KiB  
Article
Self-Doped Carbon Dots Decorated TiO2 Nanorods: A Novel Synthesis Route for Enhanced Photoelectrochemical Water Splitting
by Chau Thi Thanh Thuy, Gyuho Shin, Lee Jieun, Hyung Do Kim, Ganesh Koyyada and Jae Hong Kim
Catalysts 2022, 12(10), 1281; https://doi.org/10.3390/catal12101281 - 20 Oct 2022
Cited by 2 | Viewed by 1705
Abstract
Herein, we have successfully prepared self-doped carbon dots with nitrogen elements (NCD) in a simple one-pot hydrothermal carbonization method, using L-histidine as a new precursor. The effect of as-prepared carbon dots was studied for photoelectrochemical (PEC) water splitting by decorating NCDs upon TiO [...] Read more.
Herein, we have successfully prepared self-doped carbon dots with nitrogen elements (NCD) in a simple one-pot hydrothermal carbonization method, using L-histidine as a new precursor. The effect of as-prepared carbon dots was studied for photoelectrochemical (PEC) water splitting by decorating NCDs upon TiO2 nanorods systematically by changing the loading time from 2 h to 8 h (TiO2@NCD2h, TiO2@NCD4h, TiO2@NCD6h, and TiO2@NCD8h). The successful decorating of NCDs on TiO2 was confirmed by FE-TEM and Raman spectroscopy. The TiO2@NCD4h has shown a photocurrent density of 2.51 mA.cm−2, 3.4 times higher than the pristine TiO2. Moreover, TiO2@NCD4h exhibited 12% higher applied bias photon-to-current efficiency (ABPE) than the pristine TiO2. The detailed IPCE, Mott–Schottky, and impedance (EIS) analyses have revealed the enhanced light harvesting property, free carrier concentration, charge separation, and transportation upon introduction of the NCDs on TiO2. The obtained results clearly portray the key role of NCDs in improving the PEC performance, providing a new insight into the development of highly competent TiO2 and NCDs based photoanodes for PEC water splitting. Full article
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Review

Jump to: Research

24 pages, 8751 KiB  
Review
The Behavior of Carbon Dots in Catalytic Reactions
by Lerato L. Mokoloko, Roy P. Forbes and Neil J. Coville
Catalysts 2023, 13(8), 1201; https://doi.org/10.3390/catal13081201 - 11 Aug 2023
Cited by 1 | Viewed by 1090
Abstract
Since their discovery in 2004, carbon dots (CDs), with particle sizes < 10 nm, have found use in various applications, mainly based on the material’s fluorescent properties. However, other potential uses of CDs remain relatively unexplored when compared to other carbon-based nanomaterials. In [...] Read more.
Since their discovery in 2004, carbon dots (CDs), with particle sizes < 10 nm, have found use in various applications, mainly based on the material’s fluorescent properties. However, other potential uses of CDs remain relatively unexplored when compared to other carbon-based nanomaterials. In particular, the use of CDs as catalysts and as supports for use in catalytic reactions, is still in its infancy. Many studies have indicated the advantages of using CDs in catalysis, but there are difficulties associated with their stability, separation, and aggregation due to their small size. This small size does however allow for studying the interaction of small catalyst particles with small dimensional supports, including the inverse support interaction. However, recent studies have indicated that CDs are not stable under high temperature conditions (especially >250 °C; with and without a catalyst) suggesting that the CDs may agglomerate and transform under some reaction conditions. The agglomeration of the metal in a CD/metal catalyst, especially because of the CDs agglomeration and transformation at high temperature, is not always considered in studies using CDs as catalysts, as post-reaction analysis of a catalyst is not always undertaken. Further, it appears that under modest thermal reaction conditions, CDs can react with some metal ions to change their morphology, a reaction that relates to the metal reducibility. This review has thus been undertaken to indicate the advantages, as well as the limitations, of using CDs in catalytic studies. The various techniques that have been used to evaluate these issues is given, and some examples from the literature that highlight the use of CDs in catalysis are described. Full article
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25 pages, 2971 KiB  
Review
Synthetic Methods and Applications of Carbon Nanodots
by Anjali Banger, Sakshi Gautam, Sapana Jadoun, Nirmala Kumari Jangid, Anamika Srivastava, Indra Neel Pulidindi, Jaya Dwivedi and Manish Srivastava
Catalysts 2023, 13(5), 858; https://doi.org/10.3390/catal13050858 - 09 May 2023
Cited by 6 | Viewed by 3713
Abstract
In the recent decade, carbon dots have drawn immense attention and prompted intense investigation. The latest form of nanocarbon, the carbon nanodot, is attracting intensive research efforts, similar to its earlier analogues, namely, fullerene, carbon nanotube, and graphene. One outstanding feature that distinguishes [...] Read more.
In the recent decade, carbon dots have drawn immense attention and prompted intense investigation. The latest form of nanocarbon, the carbon nanodot, is attracting intensive research efforts, similar to its earlier analogues, namely, fullerene, carbon nanotube, and graphene. One outstanding feature that distinguishes carbon nanodots from other known forms of carbon materials is its water solubility owing to extensive surface functionalization (the presence of polar surface functional groups). These carbonaceous quantum dots, or carbon nanodots, have several advantages over traditional semiconductor-based quantum dots. They possess outstanding photoluminescence, fluorescence, biocompatibility, biosensing and bioimaging, photostability, feedstock sustainability, extensive surface functionalization and bio-conjugation, excellent colloidal stability, eco-friendly synthesis (from organic matter such as glucose, coffee, tea, and grass to biomass waste-derived sources), low toxicity, and cost-effectiveness. Recent advances in the synthesis and characterization of carbon dots have been received and new insight is provided. Presently known applications of carbon dots in the fields of bioimaging, drug delivery, sensing, and diagnosis were highlighted and future applications of these astounding materials are speculated. Full article
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19 pages, 1875 KiB  
Review
Green Carbon Dots: Applications in Development of Electrochemical Sensors, Assessment of Toxicity as Well as Anticancer Properties
by Madushmita Hatimuria, Plabana Phukan, Soumabha Bag, Jyotirmoy Ghosh, Krishna Gavvala, Ashok Pabbathi and Joydeep Das
Catalysts 2023, 13(3), 537; https://doi.org/10.3390/catal13030537 - 07 Mar 2023
Cited by 7 | Viewed by 2302
Abstract
Carbon dots are one of the most promising nanomaterials which exhibit a wide range of applications in the field of bioimaging, sensing and biomedicine due to their ultra-small size, high photostability, tunable fluorescence, electrical properties, etc. However, green carbon dots synthesized from several [...] Read more.
Carbon dots are one of the most promising nanomaterials which exhibit a wide range of applications in the field of bioimaging, sensing and biomedicine due to their ultra-small size, high photostability, tunable fluorescence, electrical properties, etc. However, green carbon dots synthesized from several natural and renewable sources show some additional advantages, such as favorable biocompatibility, wide sources, low cost of production and ecofriendly nature. In this review, we will provide an update on the latest research of green carbon dots regarding their applications in cancer therapy and in the development of electrochemical sensors. Besides, the toxicity assessment of carbon dots as well as the challenges and future direction of research on their anticancer and sensing applications will be discussed. Full article
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22 pages, 2728 KiB  
Review
Carbon Quantum Dots: Synthesis, Structure, Properties, and Catalytic Applications for Organic Synthesis
by Pradeep Kumar Yadav, Subhash Chandra, Vivek Kumar, Deepak Kumar and Syed Hadi Hasan
Catalysts 2023, 13(2), 422; https://doi.org/10.3390/catal13020422 - 16 Feb 2023
Cited by 21 | Viewed by 9527
Abstract
Carbon quantum dots (CQDs), also known as carbon dots (CDs), are novel zero-dimensional fluorescent carbon-based nanomaterials. CQDs have attracted enormous attention around the world because of their excellent optical properties as well as water solubility, biocompatibility, low toxicity, eco-friendliness, and simple synthesis routes. [...] Read more.
Carbon quantum dots (CQDs), also known as carbon dots (CDs), are novel zero-dimensional fluorescent carbon-based nanomaterials. CQDs have attracted enormous attention around the world because of their excellent optical properties as well as water solubility, biocompatibility, low toxicity, eco-friendliness, and simple synthesis routes. CQDs have numerous applications in bioimaging, biosensing, chemical sensing, nanomedicine, solar cells, drug delivery, and light-emitting diodes. In this review paper, the structure of CQDs, their physical and chemical properties, their synthesis approach, and their application as a catalyst in the synthesis of multisubstituted 4H pyran, in azide-alkyne cycloadditions, in the degradation of levofloxacin, in the selective oxidation of alcohols to aldehydes, in the removal of Rhodamine B, as H-bond catalysis in Aldol condensations, in cyclohexane oxidation, in intrinsic peroxidase-mimetic enzyme activity, in the selective oxidation of amines and alcohols, and in the ring opening of epoxides are discussed. Finally, we also discuss the future challenges in this research field. We hope this review paper will open a new channel for the application of CQDs as a catalyst in organic synthesis. Full article
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