Hydrogenation and dehydrogenation of nitrogen-doped graphene investigated by X-ray photoelectron spectroscopy

In this study, nitrogen doped graphene (NG) was prepared by using hydrothermal treatment of graphene oxide (GO) and ethylene diamine (EDA). The surface chemistry of the reduced graphene oxide (rGO) and the NG was investigated by the X-ray photoelectron spectroscopy (XPS). The results revealed that there were four kinds of nitrogen substitution: pyrollic N, pyridinic N, graphitic N and C-NH2. Further, the electrical measurements illustrated that the NG had superior capacitive performance than that of the rGO. Specifically, the maximum specific capacitance of NG was 200.6 F/g due to the double-layer capacitive and pseudocapacitive effect from the nitrogen-doped graphene. In addition, the present studies showed that the EDA was not only choose as nitrogen doping source but also played a key role in reduction.

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Efficient Removal of Bisphenol A Using Nitrogen-Doped Graphene-Like Plates from Green Petroleum Coke

Molecules ◽

10.3390/molecules25153543 ◽

2020 ◽

Vol 25 (15) ◽

pp. 3543

Author(s):

Zhipeng Liu ◽

Quanyong Wang ◽

Bei Zhang ◽

Tao Wu ◽

Yujiang Li

Keyword(s):

Bisphenol A ◽

Petroleum Coke ◽

Photoelectron Spectroscopy ◽

Oil Refining ◽

Bet Surface Area ◽

X Ray ◽

Nitrogen Doped ◽

Nitrogen Doped Graphene ◽

Doped Graphene ◽

Green Petroleum Coke

Green petroleum coke, a form of industrial waste produced in the oil-refining process, was used to synthesize nitrogen-doped graphene-like plates (N-GLPs) together with melamine. In this study, characterization and batch experiments were performed to elucidate the interaction mechanism of N-GLPs and bisphenol A (BPA). Structural analysis of N-GLPs, including scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Brunauer-Emmett-Teller (BET), and X-ray photoelectron spectroscopy (XPS), showed an obvious graphene-like structure and successful nitrogen doping. In addition, compared with 8.0 m2/g for green petroleum coke, the BET surface area of N-GLPs markedly increased to 96.6 m2/g. The influences of various factors, including contact time, temperature, and initial pH on BPA removal efficiency were investigated. It was found that 92.0% of BPA was successfully removed by N-GLPs at 50 °C. Based on the adsorption experiments, it was shown that electrostatic attraction, hydrogen bonding, and π-π interaction enhanced the adsorption capacity of N-GLPs for BPA. According to the thermodynamic data, the adsorption process was spontaneous, physical, and endothermic in nature. Therefore, N-GLPs are efficient adsorbent material to remove BPA from wastewater.

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Hydrothermal Synthesis of Few-Layer and Edge-Rich Cobalt-Doped Molybdenum Selenide/Nitrogenated Graphene Composite and Investigation of Its Electrocatalytic Activity for Hydrogen Evolution Reaction

NANO ◽

10.1142/s1793292016501071 ◽

2016 ◽

Vol 11 (10) ◽

pp. 1650107 ◽

Cited By ~ 3

Author(s):

Ming Ou ◽

Lin Ma ◽

Limei Xu ◽

Zhuomei Yang ◽

Haizhen Li

Keyword(s):

Electron Microscopy ◽

Hydrogen Evolution ◽

Hydrogen Evolution Reaction ◽

Photoelectron Spectroscopy ◽

Hydrothermal Route ◽

X Ray ◽

Graphene Composite ◽

Molybdenum Selenide ◽

Nitrogen Doped Graphene ◽

Doped Graphene

Cobalt-doped MoSe2/nitrogenated graphene composite has been successfully synthesized via a facile hydrothermal route and is investigated as an electrocatalyst for hydrogen evolution reaction (HER). The as-prepared samples are well characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS) and Raman spectrum. The results reveal that Co-doped MoSe2 nanosheets which are characteristic of few layers (2–4 layers) and abundant exposed active edge sites are well anchored on the nitrogen-doped graphene sheets to constitute robust composites. When evaluated as catalysts for HER, the obtained composites demonstrate superior electrocatalytic activities toward HER.

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Nitrogen-Doped Graphene: The Influence of Doping Level on the Charge-Transfer Resistance and Apparent Heterogeneous Electron Transfer Rate

Sensors ◽

10.3390/s20071815 ◽

2020 ◽

Vol 20 (7) ◽

pp. 1815 ◽

Cited By ~ 4

Author(s):

Maria Coros ◽

Codruta Varodi ◽

Florina Pogacean ◽

Emese Gal ◽

Stela M. Pruneanu

Keyword(s):

Doping Level ◽

Transfer Rate ◽

Charge Transfer Resistance ◽

Electron Transfer Rate ◽

Transfer Resistance ◽

X Ray ◽

Nitrogen Doped ◽

Heterogeneous Electron Transfer ◽

Nitrogen Doped Graphene ◽

Doped Graphene

Three nitrogen-doped graphene samples were synthesized by the hydrothermal method using urea as doping/reducing agent for graphene oxide (GO), previously dispersed in water. The mixture was poured into an autoclave and placed in the oven at 160 °C for 3, 8 and 12 h. The samples were correspondingly denoted NGr-1, NGr-2 and NGr-3. The effect of the reaction time on the morphology, structure and electrochemical properties of the resulting materials was thoroughly investigated using scanning electron microscopy (SEM) Raman spectroscopy, X-ray powder diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), elemental analysis, Cyclic Voltammetry (CV) and electrochemical impedance spectroscopy (EIS). For NGr-1 and NGr-2, the nitrogen concentration obtained from elemental analysis was around 6.36 wt%. In the case of NGr-3, a slightly higher concentration of 6.85 wt% was obtained. The electrochemical studies performed with NGr modified electrodes proved that the charge-transfer resistance (Rct) and the apparent heterogeneous electron transfer rate constant (Kapp) depend not only on the nitrogen doping level but also on the type of nitrogen atoms found at the surface (pyrrolic-N, pyridinic-N or graphitic-N). In our case, the NGr-1 sample which has the lowest doping level and the highest concentration of pyrrolic-N among all nitrogen-doped samples exhibits the best electrochemical parameters: a very small Rct (38.3 Ω), a large Kapp (13.9 × 10−2 cm/s) and the best electrochemical response towards 8-hydroxy-2′-deoxyguanosine detection (8-OHdG).

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High Reversible Capacity of Nitrogen-Doped Graphene as an Anode Material for Lithium-Ion Batteries

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1070-1072.459 ◽

2014 ◽

Vol 1070-1072 ◽

pp. 459-464

Author(s):

Chang Jing Fu ◽

Shuang Li ◽

Qian Wang

Keyword(s):

Graphene Oxide ◽

Electron Microscope ◽

Lithium Ion Batteries ◽

Current Density ◽

Lithium Ion ◽

X Ray ◽

Nitrogen Doped ◽

Nitrogen Doped Graphene ◽

Doped Graphene ◽

A Current

Nitrogen-doped graphene (N-rGO) was synthesized in the process of preparation of reduced graphene oxide from the expanded graphite through the improved Hummers’ method. The morphology, structure and composition of nitrogen-doped graphene oxide (GO) and N-rGO were characterized by scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). The nitrogen content of N-rGO was approximately 5 at.%. The electrochemical performances of N-rGO as anode materials for lithium-ion batteries were evaluated in coin-type cells versus metallic lithium. Results showed that the obtained N-rGO exhibited a higher reversible specific capacity of 519 mAh g-1 at a current density of 100 mA⋅g-1 and 207.5 mAh⋅g-1 at a current density of 2000 mA⋅g-1. The excellent cycling stability and high-rate capability of N-rGO as anodes of lithium-ion battery were attributed to the large number of surface defects caused by the nitrogen doping, which facilitates the fast transport of Li-ion and electron on the interface of electrolyte/electrode.

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Photolysis of Fluorinated Graphites with Embedded Acetonitrile Using a White-Beam Synchrotron Radiation

Nanomaterials ◽

10.3390/nano12020231 ◽

2022 ◽

Vol 12 (2) ◽

pp. 231

Author(s):

Galina I. Semushkina ◽

Yuliya V. Fedoseeva ◽

Anna A. Makarova ◽

Dmitry A. Smirnov ◽

Igor P. Asanov ◽

...

Keyword(s):

Synchrotron Radiation ◽

Photoelectron Spectroscopy ◽

X Ray ◽

Photon Irradiation ◽

Nexafs Spectroscopy ◽

White Beam ◽

Nitrogen Doped Graphene ◽

Doped Graphene ◽

X Ray Absorption

Fluorinated graphitic layers with good mechanical and chemical stability, polar C–F bonds, and tunable bandgap are attractive for a variety of applications. In this work, we investigated the photolysis of fluorinated graphites with interlayer embedded acetonitrile, which is the simplest representative of the acetonitrile-containing photosensitizing family. The samples were continuously illuminated in situ with high-brightness non-monochromatized synchrotron radiation. Changes in the compositions of the samples were monitored using X-ray photoelectron spectroscopy and near-edge X-ray absorption fine structure (NEXAFS) spectroscopy. The NEXAFS N K-edge spectra showed that acetonitrile dissociates to form HCN and N2 molecules after exposure to the white beam for 2 s, and the latter molecules completely disappear after exposure for 200 s. The original composition of fluorinated matrices CF0.3 and CF0.5 is changed to CF0.10 and GF0.17, respectively. The highly fluorinated layers lose fluorine atoms together with carbon neighbors, creating atomic vacancies. The edges of vacancies are terminated with the nitrogen atoms and form pyridinic and pyrrolic units. Our in situ studies show that the photolysis products of acetonitrile depend on the photon irradiation duration and composition of the initial CFx matrix. The obtained results evaluate the radiation damage of the acetonitrile-intercalated fluorinated graphites and the opportunities to synthesize nitrogen-doped graphene materials.

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Nitrogen-doped graphene quantum dots synthesized by femtosecond laser ablation in liquid from laser induced graphene

Nanotechnology ◽

10.1088/1361-6528/ac4069 ◽

2021 ◽

Author(s):

Li Shen ◽

Sikun Zhou ◽

Fei Huang ◽

Hao Zhou ◽

Hong Zhang ◽

...

Keyword(s):

Quantum Dots ◽

Laser Ablation ◽

Femtosecond Laser ◽

Photoelectron Spectroscopy ◽

Graphene Quantum Dots ◽

Femtosecond Laser Ablation ◽

Laser Ablation In Liquid ◽

Nitrogen Doped ◽

Nitrogen Doped Graphene ◽

Doped Graphene

Abstract In this work, graphene quantum dots (GQDs) synthesized by femtosecond laser ablation in liquid (LAL) using laser-induced graphene (LIG) as the carbon source. Nitrogen-doped graphene quantum dots (N-GQDs) were successfully synthesized by adding ammonia water to the graphene suspension. The GQDs/N-GQDs structure consist of a graphitic core with oxygen and nitrogen functionalities and particle size less than 10 nm, as demonstrated by X-ray photoelectron spectroscopy, Fourier infrared spectrometer spectroscopy and transmission electron microscopy. The absorption peak and PL spectrum and quantum yield of the N-GQDs were significantly enhanced compared with the undoped GQDs. Further, the possible mechanism of synthesis GQDs is discussed. Furthermore, the N-GQDs were used as a fluorescent probe for detection of Fe3+ ions. The N-GQDs may extend the application of graphene-based materials to bioimaging, sensor and, photoelectronic.

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Study on Nitrogen-Doped Graphene Ink and Its Effects on the Heat Dissipation for the LED Lamps

Applied Sciences ◽

10.3390/app10082738 ◽

2020 ◽

Vol 10 (8) ◽

pp. 2738

Author(s):

Ah-Der Lin ◽

Wen-Kai Yu ◽

Sian Zheng Poon ◽

Cheng-Yi Chen ◽

Chao-Ming Hsu

Keyword(s):

Photoelectron Spectroscopy ◽

Heat Dissipation ◽

Light Emitting Diode ◽

Short Circuit ◽

High Heat ◽

Integrating Sphere ◽

Light Emitting ◽

Nitrogen Doped ◽

Nitrogen Doped Graphene ◽

Doped Graphene

This study explored the application of nitrogen-doped graphene (NDG) ink to the coating of light-emitting diode (LED) lamps for the thermal management. Unlike the general solutions of graphene, the NDG ink used in this study was tuned with high electrical resistance and quietly suitable for the application of the LED lamp coating, which prevented the short circuit problem; besides, the NDG ink also provided a high heat dissipation effect to improve the performance of the LED lamp. The investigation of adhesion and resistance for the NDG ink were conducted by the cross-cut test and the four-point probe resistance measurement, respectively. Three types of LED lamps including the original lamp, fin-removed lamp, and NDG-ink coated (NGC) lamp were tested for the actual operating temperature distribution by K-type thermal couples and for the lumens by the integrating sphere. The results showed that the heat dissipation of the NGC lamp was better than that of the original lamp. In addition, the inspections for the properties of NDG powder were also performed by x-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), and Raman spectroscopy. According to the inspectional results, the NDG powder had a percentage of nitrogen of about 3.8% by XPS, a surface roughness Rq of 0.9 nm by AFM, and over ten layers by Raman analysis. It showed that the NDG powder in this study belonged to the type of multi-layer graphene.

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