scholarly journals Nitrogen Functionalization of CVD Grown Three-Dimensional Graphene Foam for Hydrogen Evolution Reactions in Alkaline Media

Materials ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 4952
Author(s):  
Daniela Ion-Ebrașu ◽  
Radu Dorin Andrei ◽  
Stanică Enache ◽  
Simona Căprărescu ◽  
Constantin Cătălin Negrilă ◽  
...  
Keyword(s):  
Hydrogen Evolution ◽  
Photoelectron Spectroscopy ◽  
Hydrothermal Process ◽  
Three Dimensional ◽  
Chemical Vapor ◽  
Alkaline Media ◽  
Active Nitrogen ◽  
Graphene Foam ◽  
Graphene Layers ◽  
Nitrogen Doped

Three-dimensional graphene foam (3D-GrFoam) is a highly porous structure and sustained lattice formed by graphene layers with sp2 and sp3 hybridized carbon. In this work, chemical vapor deposition (CVD)—grown 3D-GrFoam was nitrogen-doped and platinum functionalized using hydrothermal treatment with different reducing agents (i.e., urea, hydrazine, ammonia, and dihydrogen hexachloroplatinate (IV) hydrate, respectively). X-ray photoelectron spectroscopy (XPS) survey showed that the most electrochemically active nitrogen-doped sample (GrFoam3N) contained 1.8 at % of N, and it exhibited a 172 mV dec−1 Tafel plot associated with the Volmer–Heyrovsky hydrogen evolution (HER) mechanism in 0.1 M KOH. By the hydrothermal process, 0.2 at % of platinum was anchored to the graphene foam surface, and the resultant sample of GrFoamPt yielded a value of 80 mV dec−1 Tafel associated with the Volmer–Tafel HER mechanism. Furthermore, Raman and infrared spectroscopy analysis, as well as scanning electron microscopy (SEM) were carried out to understand the structure of the samples.

scholarly journals Nitrogen-Doped Flower-Like Hybrid Structure Based on Three-Dimensional Graphene

2020 ◽  
Vol 6 (2) ◽  
pp. 40
Author(s):  
Kinshuk Dasgupta ◽  
Mahnoosh Khosravifar ◽  
Shrilekha Sawant ◽  
Paa Kwasi Adusei ◽  
Sathya Narayan Kanakaraj ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Three Dimensional ◽  
Chemical Vapor ◽  
Hybrid Structure ◽  
High Specific Surface Area ◽  
Active Nitrogen ◽  
3D Graphene ◽  
Nitrogen Doped ◽  
N Doping

A new flower-like hybrid structure consisting of nitrogen-doped 3-dimensional (3D) graphene and vertically aligned graphene has been synthesized using a combination of low-pressure chemical vapor deposition (LPCVD) and plasma-enhanced chemical vapor deposition (PECVD) techniques. Active nitrogen (N) species were found to be essential for the growth of the flower-like morphology. N-doping was responsible for enhanced electrical conductivity and wettability of the obtained nano-carbon hybrid structure. Based on the conducted studies a growth mechanism has been proposed. The high specific surface area, low resistance to charge transfer and enhanced specific capacitance of this nitrogen-doped hybrid structure, makes it an excellent candidate material for supercapacitors.

A binder- and carbon-free hydrogen evolution electro-catalyst in alkaline media based on nitrogen-doped Ni(OH)2 nanobelts/3D Ni foam

2020 ◽  
Vol 22 (8) ◽  
Author(s):  
ChuiTao Zeng ◽  
KaiLing Zhou ◽  
YuHong Jin ◽  
QianQian Zhang ◽  
JingBing Liu ◽  
...  
Keyword(s):  
Hydrogen Evolution ◽  
Alkaline Media ◽  
Ni Foam ◽  
Nitrogen Doped ◽  
Free Hydrogen

Heteroepitaxial Nucleation and Growth of Ge ON Si(100) Surfaces Using Remote Plasma Enhanced Chemical Vapor Deposition

1988 ◽  
Vol 116 ◽  
Author(s):  
R.A. Rudder ◽  
S.V. Hattangady ◽  
D.J. Vitkavage ◽  
R.J. Markunas
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Photoelectron Spectroscopy ◽  
Three Dimensional ◽  
Chemical Vapor ◽  
Layer By Layer ◽  
Heteroepitaxial Growth ◽  
Remote Plasma ◽  
Dimensional Growth ◽  
Diffraction Patterns

Heteroepitaxial growth of Ge on Si(100) has been accomplished using remote plasma enhanced chemical vapor deposition at 300*#x00B0;C. Reconstructed surfaces with diffraction patterns showing non-uniform intensity variations along the lengths of the integral order streaks are observed during the first 100 Å of deposit. This observation of an atomically rough surface during the initial stages of growth is an indication of three-dimensional growth. As the epitaxial growth proceeds, the diffraction patterns become uniform with extensive streaking on both the integral and fractional order streaks. Subsequent growth, therefore, takes place in a layer-by-layer, two-dimensional mode. X-ray photoelectron spectroscopy of the early nucleation stages, less than 80 Å, show that there is uniform coverage with no evidence of island formation.

Well-dispersed molybdenum nitrides on a nitrogen-doped carbon matrix for highly efficient hydrogen evolution in alkaline media

2017 ◽  
Vol 5 (39) ◽  
pp. 20932-20937 ◽  
Author(s):  
Zhe Lv ◽  
Muhammad Tahir ◽  
Xuewei Lang ◽  
Gang Yuan ◽  
Lun Pan ◽  
...  
Keyword(s):  
Hydrogen Evolution ◽  
Carbon Matrix ◽  
Alkaline Media ◽  
Alkaline Electrolyte ◽  
Nitrogen Doped ◽  
Highly Efficient ◽  
Molybdenum Nitrides ◽  
Nitrogen Doped Carbon

A strategy is designed to fabricate well-dispersed Mo2N nanoparticles on nitrogen-doped carbon as a new and effective electrocatalyst for hydrogen evolution in alkaline electrolyte.

Solvent-mediated crystalline phases of NixSy anchored on rGO sheets as electrocatalysts for hydrogen evolution application

2019 ◽  
Vol 12 (01) ◽  
pp. 1850089
Author(s):  
Hou Lin Yu ◽  
Wenliang Shi ◽  
Shuaishuai Li ◽  
Junma Zhang ◽  
Xiaobo Zhang ◽  
...  
Keyword(s):  
Ethylene Glycol ◽  
Hydrogen Evolution ◽  
Hydrothermal Process ◽  
Volume Ratio ◽  
Decisive Role ◽  
Catalytic Performance ◽  
Deionized Water ◽  
Alkaline Media ◽  
One Pot ◽  
Alkaline Environments

A facile, one-pot solvent-mediated hydrothermal process was adopted to prepare nickel sulfide nanoparticles decorated on reduced graphene oxide (NixSy/rGO) as electrocatalysts for hydrogen evolution reaction (HER). The designed solvent (ethylene glycol and deionized water) played a decisive role in controlling both crystalline phase and morphology of NixSy/rGO composites, leading to pure [Formula: see text]-NiS nanoparticles uniformly distributed on rGO sheets under suitable volume ratio of ethylene glycol and deionized water (2:1). The optimized [Formula: see text]-NiS/rGO showed prominent HER catalytic performance with a rather small Tafel slope of 93[Formula: see text]mV/decade and prominent current density of 10[Formula: see text]mA/cm2 at the overpotential of 177[Formula: see text]mV in alkaline environments when compared to pristine [Formula: see text]-NiS and NiS2/rGO catalysts. The excellent catalytic performance and long-term durability even after 8000 cycles confirmed the potential of [Formula: see text]-NiS/rGO composites as efficient electrocatalysts for HER in the alkaline media.

scholarly journals One-step chemical vapor deposition synthesis and supercapacitor performance of nitrogen-doped porous carbon–carbon nanotube hybrids

2017 ◽  
Vol 8 ◽  
pp. 2669-2679 ◽  
Author(s):  
Egor V Lobiak ◽  
Lyubov G Bulusheva ◽  
Ekaterina O Fedorovskaya ◽  
Yury V Shubin ◽  
Pavel E Plyusnin ◽  
...  
Keyword(s):  
Chemical Vapor Deposition ◽  
Hybrid Materials ◽  
Vapor Deposition ◽  
Porous Carbon ◽  
Photoelectron Spectroscopy ◽  
Electrochemical Impedance ◽  
Chemical Vapor ◽  
Carbon Surface ◽  
Simultaneous Formation ◽  
Nitrogen Doped

Novel nitrogen-doped carbon hybrid materials consisting of multiwalled nanotubes and porous graphitic layers have been produced by chemical vapor deposition over magnesium-oxide-supported metal catalysts. CN x nanotubes were grown on Co/Mo, Ni/Mo, or Fe/Mo alloy nanoparticles, and MgO grains served as a template for the porous carbon. The simultaneous formation of morphologically different carbon structures was due to the slow activation of catalysts for the nanotube growth in a carbon-containing gas environment. An analysis of the obtained products by means of transmission electron microscopy, thermogravimetry and X-ray photoelectron spectroscopy methods revealed that the catalyst's composition influences the nanotube/porous carbon ratio and concentration of incorporated nitrogen. The hybrid materials were tested as electrodes in a 1M H2SO4 electrolyte and the best performance was found for a nitrogen-enriched material produced using the Fe/Mo catalyst. From the electrochemical impedance spectroscopy data, it was concluded that the nitrogen doping reduces the resistance at the carbon surface/electrolyte interface and the nanotubes permeating the porous carbon provide fast charge transport in the cell.

Non-precious alloy encapsulated in nitrogen-doped graphene layers derived from MOFs as an active and durable hydrogen evolution reaction catalyst

2015 ◽  
Vol 8 (12) ◽  
pp. 3563-3571 ◽  
Author(s):  
Yang Yang ◽  
Zhengyan Lun ◽  
Guoliang Xia ◽  
Fangcai Zheng ◽  
Mengni He ◽  
...  
Keyword(s):  
Hydrogen Evolution ◽  
Hydrogen Evolution Reaction ◽  
Feco Alloy ◽  
Graphene Layers ◽  
Nitrogen Doped ◽  
Nitrogen Doped Graphene ◽  
Doped Graphene

An FeCo alloy covered with nitrogen doped graphene is prepared by direct annealing of Fe3[Co(CN)6]2nanoparticles, exhibiting efficient HER catalysis.

Synthesis of Graphene-ZnO Heterogeneous Nanostructures by Chemical Vapor Deposition

2011 ◽  
Vol 1348 ◽  
Author(s):  
Jian Lin ◽  
Miroslav Penchev ◽  
Guoping Wang ◽  
Rajat K Paul ◽  
Jiebin Zhong ◽  
...  
Keyword(s):  
Optical Properties ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Three Dimensional ◽  
Chemical Vapor ◽  
Building Blocks ◽  
Zno Nanostructures ◽  
Large Area ◽  
Graphene Layers

ABSTRACTIn this work, we report the synthesis and characterization of three dimensional heterostructures graphene nanostructures (HGN) comprising continuous large area graphene layers and ZnO nanostructures, fabricated via chemical vapor deposition. Characterization of large area HGN demonstrates that it consists of 1-5 layers of graphene, and exhibits high optical transmittance and enhanced electrical conductivity. Electron microscopy investigation of the three dimensional heterostructures shows that the morphology of ZnO nanostructures is highly dependent on the growth temperature. It is observed that ordered crystalline ZnO nanostructures are preferably grown along the <0001> direction. Ultraviolet spectroscopy indicates that the CVD grown HGN layers has excellent optical properties. A combination of electrical and optical properties of graphene and ZnO building blocks in ZnO based HGN provides unique characteristics for opportunities in future optoelectronic devices.

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