Honeycomb like copper‐cobalt nanostructures and their synergy with carbon supports for electrooxidation of carbinol

2020 ◽  
Author(s):  
Divya C. Sesu ◽  
Anita Swami ◽  
Bhalchandra Kakade
Keyword(s):  
Carbon Supports ◽  
Cobalt Nanostructures

The ionic strength dependence of chromatin folding

1978 ◽  
Vol 36 (2) ◽  
pp. 220-221
Author(s):  
F. Thoma ◽  
TH. Koller
Keyword(s):  
Electron Microscopy ◽  
Electron Microscope ◽  
Ionic Strength ◽  
Specimen Preparation ◽  
Preparation Technique ◽  
Carbon Supports ◽  
Ionic Strength Dependence ◽  
Chromatin Folding ◽  
Strength Dependence ◽  
Preparation Techniques

Under a variety of electron microscope specimen preparation techniques different forms of chromatin appearance can be distinguished: beads-on-a-string, a 100 Å nucleofilament, a 250 Å fiber and a compact 300 to 500 Å fiber.Using a standardized specimen preparation technique we wanted to find out whether there is any relation between these different forms of chromatin or not. We show that with increasing ionic strength a chromatin fiber consisting of a row of nucleo- somes progressively folds up into a solenoid-like structure with a diameter of about 300 Å.For the preparation of chromatin for electron microscopy the avoidance of stretching artifacts during adsorption to the carbon supports is of utmost importance. The samples are fixed with 0.1% glutaraldehyde at 4°C for at least 12 hrs. The material was usually examined between 24 and 48 hrs after the onset of fixation.

Comparison of TEM and STM observations of small silver clusters on different carbon supports

1990 ◽  
Vol 48 (4) ◽  
pp. 264-265
Author(s):  
Bernd Tesche ◽  
Tobias Schilling
Keyword(s):  
Vibration Isolation ◽  
Pyrolytic Graphite ◽  
Carbon Film ◽  
Silver Clusters ◽  
Carbon Supports ◽  
Stacking Order ◽  
System P ◽  
High Resolution Tem ◽  
High Degree ◽  
Degree Of Order

The objective of our work is to determine:a) whether both of the imaging methods (TEM, STM) yield comparable data andb) which method is better suited for a reliable structure analysis of microclusters smaller than 1.5 nm, where a deviation of the bulk structure is expected.The silver was evaporated in a bell-jar system (p 10−5 pa) and deposited onto a 6 nm thick amorphous carbon film and a freshly cleaved highly oriented pyrolytic graphite (HOPG).The average deposited Ag thickness is 0.1 nm, controlled by a quartz crystal microbalance at a deposition rate of 0.02 nm/sec. The high resolution TEM investigations (100 kV) were executed by a hollow-cone illumination (HCI). For the STM investigations a commercial STM was used. With special vibration isolation we achieved a resolution of 0.06 nm (inserted diffraction image in Fig. 1c). The carbon film shows the remarkable reduction in noise by using HCI (Fig. 1a). The HOPG substrate (Fig. 1b), cleaved in sheets thinner than 30 nm for the TEM investigations, shows the typical arrangement of a nearly perfect stacking order and varying degrees of rotational disorder (i.e. artificial single crystals). The STM image (Fig. 1c) demonstrates the high degree of order in HOPG with atomic resolution.

Carbon Supports Mitigate Resistivity Limitations in Ni-Mo Alkaline Hydrogen Evolution Electrocatalysts

2018 ◽  
Author(s):  
Rituja Patil ◽  
Aayush Mantri ◽  
Stephen House ◽  
Judith C. Yang ◽  
James McKone
Keyword(s):  
Oxide Layer ◽  
Hydrogen Evolution ◽  
Interfacial Resistance ◽  
Carbon Supports ◽  
Vulcan Carbon

We have studied the composition and morphology of Ni-Mo alloys. These alloys consist of a Ni-rich core surrounded by Mo-rich oxide layer. The HER activity of Ni-Mo alloys was seen to be limited by interfacial resistance rather than kinetic and solution transport. Vulcan carbon, a conductive support mitigate the resistive limitations by providing conductive percolation networks.

scholarly journals Transition-Metal Nanoparticle Catalysts Anchored on Carbon Supports via Short-Chain Alginate Linkers

2021 ◽  
Author(s):  
Joakim Tafjord ◽  
Erling Rytter ◽  
Anders Holmen ◽  
Rune Myrstad ◽  
Ingeborg-Helene Svenum ◽  
...  
Keyword(s):  
Transition Metal ◽  
Metal Nanoparticle ◽  
Short Chain ◽  
Carbon Supports ◽  
Nanoparticle Catalysts

scholarly journals Hierarchical Porous, N-Containing Carbon Supports for High Loading Sulfur Cathodes

Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 408
Author(s):  
Jae-Woo Park ◽  
Hyun Jin Hwang ◽  
Hui-Ju Kang ◽  
Gazi A. K. M. Rafiqul Bari ◽  
Tae-Gyu Lee ◽  
...  
Keyword(s):  
High Energy ◽  
High Energy Density ◽  
High Loading ◽  
Carbon Supports ◽  
Structure Directing Agent ◽  
Shuttle Effect ◽  
Main Challenge ◽  
Hierarchical Porous ◽  
Hollow Carbon ◽  
A Minor

The lithium-polysulfide (LiPS) dissolution from the cathode to the organic electrolyte is the main challenge for high-energy-density lithium-sulfur batteries (LSBs). Herein, we present a multi-functional porous carbon, melamine cyanurate (MCA)-glucose-derived carbon (MGC), with superior porosity, electrical conductivity, and polysulfide affinity as an efficient sulfur support to mitigate the shuttle effect. MGC is prepared via a reactive templating approach, wherein the organic MCA crystals are utilized as the pore-/micro-structure-directing agent and nitrogen source. The homogeneous coating of spherical MCA crystal particles with glucose followed by carbonization at 600 °C leads to the formation of hierarchical porous hollow carbon spheres with abundant pyridinic N-functional groups without losing their microstructural ordering. Moreover, MGC enables facile penetration and intensive anchoring of LiPS, especially under high loading sulfur conditions. Consequently, the MGC cathode exhibited a high areal capacity of 5.79 mAh cm−2 at 1 mA cm−2 and high loading sulfur of 6.0 mg cm−2 with a minor capacity decay rate of 0.18% per cycle for 100 cycles.

Effect of a heat pretreatment on the structure and properties of carbon supports for carbon membranes

2017 ◽  
Vol 95 (11) ◽  
pp. 2112-2119 ◽  
Author(s):  
Shanshan Liu ◽  
Bing Zhang ◽  
Yuan Jiang ◽  
Yonghong Wu ◽  
Tonghua Wang ◽  
...  
Keyword(s):  
Structure And Properties ◽  
Carbon Supports ◽  
Carbon Membranes ◽  
Heat Pretreatment

scholarly journals Catalytic activity of gold nanoparticles deposited on N-doped carbon-based supports in oxidation of glucose and arabinose mixtures

2021 ◽  
Author(s):  
Sebastian Franz ◽  
Nataliya D. Shcherban ◽  
Igor Bezverkhyy ◽  
Sergii A. Sergiienko ◽  
Irina L. Simakova ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Catalytic Activity ◽  
Glucose Oxidation ◽  
Glucuronic Acid ◽  
Carbon Surface ◽  
Carbon Supports ◽  
Constant Ph ◽  
Oxidation Of Glucose ◽  
Mesoporous Structures ◽  
Carbon Based

AbstractOxidation of a mixture of glucose and arabinose over Au particles deposited on porous carbons, N-doped carbons and carbon nitrides was investigated at 70 °C, under constant pH of 8, and oxygen partial pressure 0.125 atm. In particular, Au deposited on nitrogen-containing carbon-based mesoporous structures demonstrated activity in the oxidation of the sugars to the corresponding aldonic acids higher than gold deposited on undoped carbon supports (conversion of glucose up to ca. 60%, arabinose–ca. 30% after 200 min). The results can be explained by the basic nature of the supports leading to an increase in the polarity of the carbon surface and the oxygen activation. Glucuronic acid (with selectivity ca. 10–93.5%) together with gluconic acid was formed as a result of glucose oxidation, while arabinose was selectively oxidized to arabinonic acid.

Heck reaction catalyzed by flower-like cobalt nanostructures

2009 ◽  
Vol 10 (8) ◽  
pp. 1178-1183 ◽  
Author(s):  
Hongling Qi ◽  
Wu Zhang ◽  
Xiang Wang ◽  
Hong Li ◽  
Jie Chen ◽  
...  
Keyword(s):  
Heck Reaction ◽  
Cobalt Nanostructures
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