Effect of synthesis conditions on the morphological and electrochemical properties of nitrogen-doped porous carbon materials

Kachmar, Andrii; Boichuk, Volodymyr; Budzulyak, І. М.; Kotsyubynsky, Volodymyr; Rachiy, B. I.; Lisovskiy, R. P.

doi:10.1080/1536383x.2019.1618840

Cited by 15 publications

(9 citation statements)

References 10 publications

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“…The interplanar distances for GO depend on multiply factors, including the oxidation degree, the number of water molecules into the interlayer space as well as the lateral dimensions of the packages and the presence of chemisorbed functional groups on the graphene layers [18]. The distance between the basal planes for bulk graphite is 0.335 nm [19].…”

Section: Resultsmentioning

confidence: 99%

Structural, morphological and electrical properties of graphene oxides obtained by Hummers, Tour and modified methods: a comparative study

Kotsyubynsky

Boychuk

Будзуляк

et al. 2021

Phys. Chem. Solid St.

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The aim of this paper is the comparison of structural, morphological and electrical properties of thermally extended graphite synthesized by chemical oxidation of graphite with sulfur of nitric acids at all other same conditions. Thermal treatments of graphite intercalation compounds were performed at a temperature of 600°C on the air for 10 min but additional annealing in temperature range of 100-600oC for 1 hour was done. The obtained materials were characterized by XRD, Raman spectroscopy and impedance spectroscopy. The evolution of structural ordering of thermally extended graphite samples at increasing of annealing temperature was traced. It was determined that the additional annealing allows to control the electrical conductivity and structural disordering degree of extended graphite samples that is useful for preparation of efficient current collectors for electrochemical capacitors.

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Section: Resultsmentioning

confidence: 99%

Structural, morphological and electrical properties of graphene oxides obtained by Hummers, Tour and modified methods: a comparative study

Kotsyubynsky

Boychuk

Будзуляк

et al. 2021

Phys. Chem. Solid St.

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“…In view of an ever-growing depend on electricity, shrinkage of the carbon-based fossil fuel deposits and increasing environmental concerns, research on alternative energy sources based on nanomaterials expands [1][2][3]. The family of direct bandgap semiconductors like Cu2ZnSnS4 is considered to be one of the promising absorber materials for the nextgeneration photovoltaics, due to earth-abundant and nontoxic constituents, as wells as appropriately high coefficient of solar light absorption (~ 10 4 cm -1 ) [4].…”

Section: Introductionmentioning

confidence: 99%

Colloidal Cu2ZnSnS4-based and Ag-doped Nanocrystals: Synthesis and Raman Spectroscopy Study

Dzhagan

Kapush

Budzulyak

et al. 2021

Phys. Chem. Solid St.

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Cu2ZnSnS4 (CZTS) is one of the promising materials for absorber layers of new-generation thin film solar cells. Various synthetic routes of materials preparation and structural characterization have been explored so far. Further tuning of the CZTS properties is realized via partial substitution of the cations. Here we have used an affordable and scalable method of synthesizing colloidal CZTS nanocrystals (NC) in an aqueous solution. Variation of the synthesis parameters, in particular pH of the solution, was employed to improve the crystallinity of the NCs. Furthermore, CZTS NCs with partial substitution of Cu for Ag were also successfully synthesized. Raman spectroscopy was employed as a prime tool of structural characterization of the NCs obtained, along with optical absorption spectroscopy and ab initio DFT lattice dynamics calculations. An experimentally observed slight upward shift of the main phonon Raman peak upon increase of the Ag content in (AgxCu1-x)2ZnSnS4 NCs is in agreement with the trend predicted by DFT calculation. No pure Ag2ZnSnS4 NCs could be formed, indicating a critical role of Cu in forming the kesterite structure NCs under given synthesis conditions in an aqueous medium.

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“…Contrary, the Nyquist plots of all rGO materials show that the bias potential is nearly vertical and at high frequency shows a very small semicircle, which indicates an ideal capacitive behavior, i. e., very low charge‐transfer resistance with high electrolyte diffusion inside the rGO electrode [44] . Mott‐Schottky analysis of rGO exhibits a positive slope indicating n‐type semiconductive nature of material [45] . The semicircle radius for rGO pH 12/5 wt % NiS 2 composite electrode is lower than for rGO.…”

Section: Resultsmentioning

confidence: 92%

Electrochemical Capacitor Based on Reduced Graphene Oxide/NiS₂ Composite

2022

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The use of a pyrite‐like structure transition metal dichalcogenides (TMDs) such as NiS2 is not reported as frequently as layered structured TMDs in electrochemical capacitors. Our study shows a reduced graphene oxide (rGO) preparation and its further use as a substrate for the deposition of NiS2 during the hydrothermal reaction. The influence of pH for the GO solution on the structural and textural properties of the resultant rGO was explained in detail by using Raman spectroscopy, UV, X‐ray diffraction (XRD), scanning electron microscopy (SEM) and nitrogen sorption at 77 K. The electrochemical response of the rGO samples obtained from various pH solutions was studied and compared in symmetric two electrode Swagelok® cells. As a result, rGO pH 12 was chosen for further modification with NiS2. The average size of the crystallites, and electronic structure of the rGO/NiS2 composite have been determined. The effect of the NiS2 content in the composite on the electrochemical results was further investigated. It occurred that 5 wt % NiS2 in the composite was sufficient for a significant improvement of the capacitive response. Interestingly, an asymmetric cell with rGO/5 wt % NiS2 working as a positive electrode and rGO pH 12 as a negative electrode was able to reach a high capacitance of 165 F g−1 at 0.2 A g−1 with 92 % coulombic and 79 % energetic efficiency.

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Effect of synthesis conditions on the morphological and electrochemical properties of nitrogen-doped porous carbon materials

Cited by 15 publications

References 10 publications

Structural, morphological and electrical properties of graphene oxides obtained by Hummers, Tour and modified methods: a comparative study

Structural, morphological and electrical properties of graphene oxides obtained by Hummers, Tour and modified methods: a comparative study

Colloidal Cu2ZnSnS4-based and Ag-doped Nanocrystals: Synthesis and Raman Spectroscopy Study

Electrochemical Capacitor Based on Reduced Graphene Oxide/NiS₂ Composite

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Effect of synthesis conditions on the morphological and electrochemical properties of nitrogen-doped porous carbon materials

Cited by 15 publications

References 10 publications

Structural, morphological and electrical properties of graphene oxides obtained by Hummers, Tour and modified methods: a comparative study

Structural, morphological and electrical properties of graphene oxides obtained by Hummers, Tour and modified methods: a comparative study

Colloidal Cu2ZnSnS4-based and Ag-doped Nanocrystals: Synthesis and Raman Spectroscopy Study

Electrochemical Capacitor Based on Reduced Graphene Oxide/NiS2 Composite

Contact Info

Product

Resources

About

Electrochemical Capacitor Based on Reduced Graphene Oxide/NiS₂ Composite