scholarly journals One-step synthesis of carbon-supported electrocatalysts

2020 ◽  
Vol 11 ◽  
pp. 1419-1431
Author(s):  
Sebastian Tigges ◽  
Nicolas Wöhrl ◽  
Ivan Radev ◽  
Ulrich Hagemann ◽  
Markus Heidelmann ◽  
...  
Keyword(s):  
Hybrid Material ◽  
Chemical Vapor ◽  
Narrow Particle Size Distribution ◽  
Long Term Stability ◽  
Operational Lifetime ◽  
Metal Acetylacetonate ◽  
One Step ◽  
Supported Electrocatalysts ◽  
Platinum Loading

Cost-efficiency, durability, and reliability of catalysts, as well as their operational lifetime, are the main challenges in chemical energy conversion. Here, we present a novel, one-step approach for the synthesis of Pt/C hybrid material by plasma-enhanced chemical vapor deposition (PE-CVD). The platinum loading, degree of oxidation, and the very narrow particle size distribution are precisely adjusted in the Pt/C hybrid material due to the simultaneous deposition of platinum and carbon during the process. The as-synthesized Pt/C hybrid materials are promising electrocatalysts for use in fuel cell applications as they show significantly improved electrochemical long-term stability compared to the industrial standard HiSPEC 4000. The PE-CVD process is furthermore expected to be extendable to the general deposition of metal-containing carbon materials from other commercially available metal acetylacetonate precursors.

Fabrication of Boron Compensated Hydrogenated Amorphous Silicon Films with Significantly Improved Stability Using Plasma Enhanced Chemical Vapor Deposition Technique

1995 ◽  
Vol 377 ◽  
Author(s):  
Mohan K. Bhan
Keyword(s):  
Chemical Vapor ◽  
Short Term ◽  
Term Stability ◽  
Long Term Stability ◽  
Vapor Deposition Technique ◽  
Improved Stability ◽  
Donor Acceptor ◽  
B Doping ◽  
The Stability

ABSTRACTWe have systematically investigated the effects of addition of sub-ppm levels of boron on the stability of a-Si:H films and p-i-n devices, deposited by PE-CVD technique. The films thus produced with appropriate amounts of boron, show a significant improvement in stability, when soaked under both AM 1.5 (short-term) as well as 10×sun (long-term) illumination conditions. The opto-electronic properties of the films are quite respectable It is concluded that boron compensates the native impurities by forming donor-acceptor pairs, which reduces the “fast” defects and hence the initial degradation of the films. It is also speculated that boron may also be improving the short-term stability, by reducing the recombination of light generated electrons and holes, by converting D° into D+ states. The long-term stability appears to get affected by hydrogen dilution which seems to reduce the amount of “slow” defects. As a result of B doping of i-layer, the initial conversion efficiency of the devices decreases. It is presumed that our devices may contain an enhanced level of boron impurity, than expected, making them as worse material and to degrade less.

Synthesis of Nanosized Polymer Particles in Nonaqueous Emulsion

2013 ◽  
Vol 1546 ◽  
Author(s):  
Robert Dorresteijn ◽  
Robert Haschick ◽  
Kevin Müller ◽  
Markus Klapper ◽  
Klaus Müllen
Keyword(s):  
Ring Opening ◽  
Continuous Phase ◽  
Size Distributions ◽  
Aqueous Emulsion ◽  
Long Term Stability ◽  
Dispersed Particles ◽  
One Step ◽  
Moisture Sensitive ◽  
The One

ABSTRACTIn nonaqueous emulsion, moisture-sensitive polymerizations are performed in order to generate nanoparticles, which are not accessible by common aqueous emulsion polymerization. A nonaqueous emulsion, consisting of two immiscible aprotic organic solvents, is stabilized by amphiphilic block copolymers, such as PIb-PEO or PIb-PMMA copolymer, and lead to formation of nanosized dispersed droplets. They act as dispersed “nanoreactors” for the one-step synthesis of poly(urethane) nanoparticles in a polyadditon reaction as well as poly(L-lactide) nanoparticles through ring-opening polymerization, catalyzed by a moisture-sensitive catalyst. The well-dispersed particles possess average diameters below 100 nm and have narrow size distributions owing to the long-term stability of the dispersed droplets in the continuous phase.

Properties of a-Si:H and a-SiGe:H Films Deposited by Photo-Assisted CVD

1986 ◽  
Vol 70 ◽  
Author(s):  
R. E. Rocheleau ◽  
S. C. Jackson. ◽  
S. S. Hegedus ◽  
B. N. Baron
Keyword(s):  
High Efficiency ◽  
Chemical Vapor ◽  
Photovoltaic Cell ◽  
Gas Flows ◽  
Long Term Stability ◽  
Improved Stability ◽  
Deposition Processes ◽  
P Type

ABSTRACTChemical vapor deposition techniques, in particular plasma enhanced CVD, have been used to produce high quality a-Si:H materials. Continuing research is directed toward increased device performance, improved stability, and translation of scale to commercial production. A part of this effort is the evaluation of alternate CVD techniques which in addition to providing technical options for high efficiency and long term stability are likely to lead to improved understanding of the relationships between deposition processes and material properties. A relatively new technique for depositing a-Si:H is photo-CVD which utilizes ultraviolet light to initiate the decomposition of silane or disilane. The best results from both materials properties and device efficiency points of view have been achieved using mercury sensitized photo-CVD. Recently, a 10.5% efficient a-Si:H p-i-n photovoltaic cell, fabricated by photo-CVD, was reported [1]. A limitation in photo-CVD has been preventing deposition on the UV transparent window. In this paper we describe a new photo-CVD reactor with a moveable UV-transparent Teflon film and secondary gas flows to eliminate window fouling. The deposition and opto-electronic characterization of intrinsic a-Si:H and a-SiGe:H and p-type a-SiC:H are described. Finally, preliminary results of p-i-n solar cells are presented.

Bread-inspired foaming strategy to fabricate a wine lees-based porous carbon framework for high specific energy supercapacitors

2021 ◽  
Vol 5 (19) ◽  
pp. 4965-4972
Author(s):  
Hui Peng ◽  
Yipu Xu ◽  
Yaping Jiang ◽  
Xin Wang ◽  
Rui Zhao ◽  
...  
Keyword(s):  
Energy Density ◽  
Porous Carbon ◽  
Fermentation Process ◽  
High Energy ◽  
High Energy Density ◽  
Long Term Stability ◽  
Carbon Framework ◽  
One Step ◽  
High Specific Energy

Inspired by the fermentation process of bread, a novel wine lees-based porous carbon framework (WLCF) having high energy density and excellent long-term stability is prepared via one-step sodium bicarbonate foaming and activation strategy.

One-step solid-phase boronation to fabricate self-supported porous FeNiB/FeNi foam for efficient electrocatalytic oxygen evolution and overall water splitting

2019 ◽  
Vol 7 (33) ◽  
pp. 19554-19564 ◽  
Author(s):  
Hefeng Yuan ◽  
Shumin Wang ◽  
Xundi Gu ◽  
Bin Tang ◽  
Jinping Li ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Water Splitting ◽  
Oxygen Evolution ◽  
Alkaline Medium ◽  
Solid Phase ◽  
Core Shell ◽  
Environment Friendly ◽  
Long Term Stability ◽  
One Step

A 3D core–shell-type FeNi@FeNiB electrocatalyst fabricated by environment-friendly solid-phase boronation exhibits remarkable catalytic activity and long-term stability for the OER in alkaline medium.

Nitrogen-doped graphene/carbon nanotube/Co3O4 hybrids: one-step synthesis and superior electrocatalytic activity for the oxygen reduction reaction

RSC Advances ◽  
2015 ◽  
Vol 5 (115) ◽  
pp. 94615-94622 ◽  
Author(s):  
Hengyi Lu ◽  
Yunpeng Huang ◽  
Jiajie Yan ◽  
Wei Fan ◽  
Tianxi Liu
Keyword(s):  
Carbon Nanotube ◽  
Reduction Reaction ◽  
Nitrogen Doped ◽  
Long Term Stability ◽  
Crossover Effects ◽  
Nitrogen Doped Graphene ◽  
Doped Graphene ◽  
One Step ◽  
Orr Activity

N-rGO/CNTs/Co3O4 hybrids were prepared through a simple one-step hydrothermal method, and exhibited comparable electrocatalytic ORR activity to Pt/C catalysts, excellent tolerance to methanol crossover effects, and even better long-term stability.

One-Step Surgical Correction of Transverse and Anteroposterior Maxillary Deficiencies Using Wire Fixation. A New Approach and Long-Term Stability

2017 ◽  
Vol 75 (7) ◽  
pp. 1498-1513
Author(s):  
Max Domingues Pereira ◽  
Vivian Farfel ◽  
Gabriela Pereira Ribeiro Prado ◽  
Lydia Masako Ferreira
Keyword(s):  
Surgical Correction ◽  
New Approach ◽  
Term Stability ◽  
Long Term Stability ◽  
Wire Fixation ◽  
One Step

scholarly journals Origin of High Efficiency and Long-Term Stability in Ionic Liquid Perovskite Photovoltaic

Research ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-13 ◽  
Author(s):  
Lingfeng Chao ◽  
Tingting Niu ◽  
Hao Gu ◽  
Yingguo Yang ◽  
Qi Wei ◽  
...  
Keyword(s):  
Carboxylic Acid ◽  
High Efficiency ◽  
Perovskite Solar Cells ◽  
Environment Friendly ◽  
Long Term Stability ◽  
Wide Range ◽  
One Step ◽  
Amine Groups ◽  
Perovskite Photovoltaic

Environment-friendly protic amine carboxylic acid ionic liquids (ILs) as solvents is a significant breakthrough with respect to traditional highly coordinating and toxic solvents in achieving efficient and stable perovskite solar cells (PSCs) with a simple one-step air processing and without an antisolvent treatment approach. However, it remains mysterious for the improved efficiency and stability of PSCs without any passivation strategy. Here, we unambiguously demonstrate that the three functions of solvents, additive, and passivation are present for protic amine carboxylic acid ILs. We found that the ILs have the capability to dissolve a series of perovskite precursors, induce oriented crystallization, and chemically passivate the grain boundaries. This is attributed to the unique molecular structure of ILs with carbonyl and amine groups, allowing for strong interaction with perovskite precursors by forming C=O…Pb chelate bonds and N-H…I hydrogen bonds in both solution and film. This finding is generic in nature with extension to a wide range of IL-based perovskite optoelectronics.

Silicon Field Emission Arrays Coated with CoSi2 Layer Grown by Reactive Chemical Vapor Deposition

2000 ◽  
Vol 621 ◽  
Author(s):  
Byung Wook Han ◽  
Hwa Sung Rhee ◽  
Byung Tae Ahn ◽  
Nam Yang Lee
Keyword(s):  
Chemical Vapor Deposition ◽  
Field Emission ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Emission Current ◽  
Emission Properties ◽  
Long Term Stability ◽  
Field Emission Arrays

ABSTRACTWe prepared Si emitters coated with an MOCVD CoSi2 layer to improve the emission properties. The CoSi2 layer was grown in situ by reactive chemical vapor deposition of cyclopentadienyl dicarbonyl cobalt at 650 °C. The CoSi2 layer was conformally coated on the Si emitter tips and had a twinned structure at the epitaxial CoSi2/Si interface. The CoSi2-coated Si emitters showed an enhanced emission due to the increase of the number of emitting site from Fowler-Nordheim plot. The fluctuation of emission current was reduced by CoSi2 coating. But the long-term stability was not much improved.

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