Preparation and optical properties of magnetic carbon/iron oxide hybrid dots

Hu, Yin; Wang, Ping; Bunker, Christopher E.; Teisl, Lindsay Rose; Reibold, McIver; Yan, Sijia; Qian, Haijun; He, Dawei; Sun, Ya‐Ping

doi:10.1039/c7ra07220a

Cited by 20 publications

(12 citation statements)

References 54 publications

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“…They are well remained in the spectrum of the PEI‐CDots obtained after thermal reaction process. At the wave number region below 1700 cm −1 , the NH bending absorption at 1650–1580 cm −1 , the CH bending absorption at 1460 cm −1 , and the CN stretching absorption at 1340–1020 cm −1 are substantially broadened in the spectrum of the as‐prepared dot sample, indicating that the precursor PEI is partially sacrificed in the thermal carbonization process . Though weak CO bonding is observed in XPS spectra corresponding to 8.7% atomic content of oxygen in PEI‐CDot, it is not observed in the FTIR spectrum which is probably overlapped by the broadened CN absorptions across the region from 1310 to 1050 cm −1 .…”

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confidence: 94%

Carbon Quantum Dots–Modified Interfacial Interactions and Ion Conductivity for Enhanced High Current Density Performance in Lithium–Sulfur Batteries

Chen

Lei

et al. 2018

Advanced Energy Materials

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111

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Among Li-ion-based batteries, lithium-sulfur (Li-S) battery has been regarded as a promising candidate for nextgeneration energy storage technology to meet the urgent demand for breakthroughs in every aspect of industrial standard. However, several intrinsic drawbacks within the Li-S battery system still remain unconquered. For instance, Significant progress has achieved for developing lithium-sulfur (Li-S) batteries with high specific capacities and excellent cyclic stability. However, some critical issues emerge when attempts are made to raise the areal sulfur loading and increase the operation current density to meet the standards for various industrial applications. In this work, polyethyleniminefunctionalized carbon dots (PEI-CDots) are designed and prepared for enhancing performance of the Li-S batteries with high sulfur loadings and operation under high current density situations. Strong chemical binding effects towards polysulfides and fast ion transport property are achieved in the PEI-CDots-modified cathodes. At a high current density of 8 mA cm −2 , the PEI-CDots-modified Li-S battery delivers a reversible areal capacity of 3.3 mAh cm −2 with only 0.07% capacity decay per cycle over 400 cycles at 6.6 mg sulfur loading. Detailed analysis, involving electrochemical impedance spectroscopy, cyclic voltammetry, and density functional theory calculations, is done for the elucidation of the underlying enhancement mechanism by the PEI-CDots. The strongly localized sulfur species and the promoted Li + ion conductivity at the cathode-electrolyte interface are revealed to enable high-performance Li-S batteries with high sulfur loading and large operational current. Lithium Sulfur BatteriesThe ORCID identification number(s) for the author(s) of this article can be found under https://doi.

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confidence: 94%

Carbon Quantum Dots–Modified Interfacial Interactions and Ion Conductivity for Enhanced High Current Density Performance in Lithium–Sulfur Batteries

Chen

Lei

et al. 2018

Advanced Energy Materials

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111

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“…Magnetic parameters derived from least-squares fits of the MS(T) data shown in the inset ii of Figure 6c with Equation 5The UV-Vis spectra of magnetic C-dots (Supplementary Information, Figure S3a) reveals the presence of absorption peaks at 270 nm and a hump around 320 nm, which are attributed to π-π* electron transitions of polyaromatic chromophores as well as n-π* electron transitions of carbonyl (C=O) and amine (C-N) functional groups [32, 36] [30, 41]. Although the absorptivity of aqueous dispersions of C/Fe-NPs are rather low [36,44,64,65], their aqueous dispersions display a strong blue luminescence under the UV light (Supplementary Information, Figure S3b). The fluorescence spectra of C/31Fe-NPs and C/17Fe-NPs (Figure 7) show an excitation wavelength independent contribution (λem=455 nm) that has been attributed to the presence of citrazinic acid and an excitation wavelength dependent emission at higher λex that is characteristic for carbogenic NPs [42].…”

Section: Ms(t)/msmentioning

confidence: 99%

Carbon Dots/Iron Oxide Nanoparticles With Tuneable Composition and Properties

Stachowska¹,

Gamża²,

Mellor³

et al. 2022

Preprint

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We present a simple strategy to generate a family of carbon dot/iron oxide nanoparticles (C/Fe-NPs) that relies on the thermal decomposition of iron (III) acetylacetonate in the presence of a highly fluorescent carbon-rich precursor, while polyethylene glycol serves as the passivation agent. By varying the molar ratio of the reactants, a series of C/Fe-NPs have been synthesized with tuneable elemental composition in terms of C, H, O, N, Fe. The quantum yield is enhanced from 6% to 9% as the carbon content increases from 27% to 36%, while the room temperature saturation magnetization is improved from 4.1 emu/g to 17.7 emu/g as the iron content is enriched from 17 to 31%. In addition, the C/Fe-NPs show excellent antimicrobial properties, minimal cytotoxicity and demonstrate promising bioimaging capabilities, thus showing great potential for the development of advanced diagnostic tools.

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“…These unique properties of carbon dots are mainly due to rich surface functional group which act as a stabilizing agent. Due to these extraordinary properties, carbon dots have potential application in the field of catalysis, energy storage and photovoltaic devices . Hence, to protect the iron oxides nanoparticles, C dot coating is preferably adopted, which in turn maintain the retentivity.…”

Section: Introductionmentioning

confidence: 99%

Synthesis and Characterization of Fe₃O₄/Carbon Dot Supported MnO₂ Nanoparticles for the Controlled Oxidation of Benzyl Alcohols

Prathibha¹,

Rangasamy²,

Sridhar³

et al. 2020

ChemistrySelect

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In recent past, magnetic catalyst has gained much attention because it can be easily separated from the reaction mixture. Herein we report a facile synthesis of magnetic carbon dot supported MnO 2 nanoparticles for the oxidative transformation of organic compounds. In the actual synthesis, initially Fe 3 O 4 nanoparticles were prepared by microwave assisted method and carbon dots were prepared instantaneously from glucose by simple incineration under closed condition. The synthesized carbon dots were coated over iron oxide nanoparticles via sonochemical deposition method. Further, magnetic carbon dot supported MnO 2 nanocomposite was synthesized by conventional homogeneous precipitation using potassium permanganate. The synthesized nanocomposite material was characterized using FT-IR, SEM, TEM, XRD and VSM techniques. The catalytic efficiency of the nanomaterial was successfully demonstrated for the oxidation of benzyl alcohols to benzaldehydes. The advantages of this method include, controlled oxidation of alcohols to aldehydes with broad substrate scope, the use of molecular oxygen as a green oxidant and beyond that a facile magnetic separation of the catalyst material. Moreover, the catalyst can be recycled for 5 times without much loss in its efficiency.

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Preparation and optical properties of magnetic carbon/iron oxide hybrid dots

Abstract: Carbon/Fe3O4 hybrid dots are prepared for their optical properties in reference to those of neat carbon dots.

Cited by 20 publications

References 54 publications

Carbon Quantum Dots–Modified Interfacial Interactions and Ion Conductivity for Enhanced High Current Density Performance in Lithium–Sulfur Batteries

Carbon Quantum Dots–Modified Interfacial Interactions and Ion Conductivity for Enhanced High Current Density Performance in Lithium–Sulfur Batteries

Carbon Dots/Iron Oxide Nanoparticles With Tuneable Composition and Properties

Synthesis and Characterization of Fe₃O₄/Carbon Dot Supported MnO₂ Nanoparticles for the Controlled Oxidation of Benzyl Alcohols

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Preparation and optical properties of magnetic carbon/iron oxide hybrid dots

Abstract: Carbon/Fe3O4 hybrid dots are prepared for their optical properties in reference to those of neat carbon dots.

Cited by 20 publications

References 54 publications

Carbon Quantum Dots–Modified Interfacial Interactions and Ion Conductivity for Enhanced High Current Density Performance in Lithium–Sulfur Batteries

Carbon Quantum Dots–Modified Interfacial Interactions and Ion Conductivity for Enhanced High Current Density Performance in Lithium–Sulfur Batteries

Carbon Dots/Iron Oxide Nanoparticles With Tuneable Composition and Properties

Synthesis and Characterization of Fe3O4/Carbon Dot Supported MnO2 Nanoparticles for the Controlled Oxidation of Benzyl Alcohols

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Synthesis and Characterization of Fe₃O₄/Carbon Dot Supported MnO₂ Nanoparticles for the Controlled Oxidation of Benzyl Alcohols