Author
Yury Gogotsi
Other affiliations: Qatar Airways, Clemson University, Qatar Foundation ...read more
Bio: Yury Gogotsi is an academic researcher from Drexel University. The author has contributed to research in topics: MXenes & Carbon. The author has an hindex of 171, co-authored 956 publications receiving 144520 citations. Previous affiliations of Yury Gogotsi include Qatar Airways & Clemson University.
Topics: MXenes, Carbon, Carbon nanotube, Supercapacitor, Electrolyte
Papers published on a yearly basis
Papers
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TL;DR: In this paper, a layer of Keggin-type polyphosphomolybdate (PMo 12 ) was coated on carbons through "layer-by-layer" deposition by alternating electrostatic adsorption of cationic and anionic species to add pseudocapacitance to improve current response and increase capacitance.
Abstract: Chemically modified carbon nanomaterials, such as nanodiamond (ND) soot, onionlike carbon (OLC), and carbon nanotubes (CNTs), were investigated as electrodes for electrochemical capacitors in high rate applications, that is, applications that drain power very fast. A layer of Keggin-type polyphosphomolybdate (PMo 12 ) was coated on carbons through "layer-by-layer" deposition by alternating electrostatic adsorption of cationic [i.e., poly(diallyldimethylammonium)chloride] and anionic (i.e., PMo 12 ) species to add pseudocapacitance to improve current response and increase capacitance. This modification was successful on OLCs and CNTs but not on ND soot. This difference is due to variations in surface chemistry, structure, and sp 2 /sp 3 content of those materials. In particular, the modified OLC exhibited a 20% increase in capacitance with up to 600 mF/cm 2 capacitance at 5 V/s, illustrating its high rate capability.
53 citations
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TL;DR: In this article, the effects of a high-temperature hydrogenation treatment on the sliding friction and wear behavior of nanostructured carbide-derived carbon (CDC) films in dry nitrogen and humid air environments were investigated.
Abstract: In this study, we investigated the effects of a high-temperature hydrogenation treatment on the sliding friction and wear behavior of nanostructured carbide-derived carbon (CDC) films in dry nitrogen and humid air environments. These films are produced on the surfaces of silicon carbide substrates by reacting the carbide phase with chlorine or chlorine–hydrogen gas mixtures at 1000 to 1100 °C in a sealed tube furnace. The typical friction coefficients of CDC films in open air are in the range of 0.2 to 0.25, but in dry nitrogen, the friction coefficients are 0.15. In an effort to achieve lower friction on CDC films, we developed and used a special hydrogenation process that was proven to be very effective in lowering friction of CDC films produced on SiC substrates. Specifically, the films that were post-hydrogen-treated exhibited friction coefficients as low as 0.03 in dry nitrogen, while the friction coefficients in humid air were ~0.2. The wear of Si3N4 counterface balls was hard to measure after the tests, while shallow wear tracks had formed on CDC films on SiC disks. Detailed mechanical and structural characterizations of the CDC films and sliding contact surfaces were done using a series of analytical techniques and these findings were correlated with the friction and wear behaviors of as-produced and hydrogen-treated CDC films.
53 citations
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TL;DR: In this paper, an electron transport layer (ETLTL) was used for low-temperature processed perovskite solar cells (PSCs) in photovoltaic devices, and the energy levels were calculated using the Vienna ab initio simulation package (VASP) code based on density functional theory (DFT).
Abstract: The unique properties of MXenes that arise from terminating functional groups and oxidation of MXenes make them attractive for application in photovoltaic devices like perovskite solar cells (PSCs) Here, oxidation of Ti3C2Tx hydrocolloid was carried out to tune its properties desirable for an electron transport layer (ETL) in low-temperature processed PSCs The calculations of the energy levels were carried out using the Vienna ab initio simulation package (VASP) code based on density functional theory (DFT) Oxidation of Ti3C2Tx can generate Ti–O bonds and effectively reduce the macroscopic defects of the film fabricated by spin-coating, while a transition from metallic material to semiconductor occurred after heavy oxidation A better matching of energy levels between perovskite and ETL layer in the case of a hybrid of oxidized and pristine Ti3C2Tx renders a champion power conversion efficiency (PCE) of 1829% The improvement in PCE can be attributed to the increased electron mobility in the ETL, which promotes electron transport and reduces the electron–hole recombination Hence, by presenting a simple method for high performance in PSCs by MXene-derived materials, this work demonstrates the great potential of these materials for applications in low-temperature processed PSCs and other photovoltaic technologies
53 citations
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TL;DR: The synergetic effects of the pre-intercalation of K+ ions are demonstrated to improve the charge storage of multivalent ions, as well as tune the mechanical and actuation properties of the Ti3C2 MXene.
Abstract: Two-dimensional materials, such as MXenes, are attractive candidates for energy storage and electrochemical actuators due to their high volume changes upon ion intercalation. Of special interest for boosting energy storage is the intercalation of multivalent ions such as Mg2+, which suffers from sluggish intercalation and transport kinetics due to its ion size. By combining traditional electrochemical characterization techniques with electrochemical dilatometry and contact resonance atomic force microscopy, the synergetic effects of the pre-intercalation of K+ ions are demonstrated to improve the charge storage of multivalent ions, as well as tune the mechanical and actuation properties of the Ti3C2 MXene. Our results have important implications for quantitatively understanding the charge storage processes in intercalation compounds and provide a new path for studying the mechanical evolution of energy storage materials.
53 citations
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TL;DR: In this paper, the magnetostatic interactions between carbon nanotubes filled with magnetic particles have been experimentally and theoretically studied, and it has been shown that the attraction/repulsion events are predictable, and that the suspensions of magnetic nanoparticles are attractive candidates for active elements in changeable diffraction gratings, filters, and polarizers.
Abstract: The magnetostatic interactions between carbon nanotubes filled with magnetic particles have been experimentally and theoretically studied. By making nanotubes uniformly magnetized, one eliminates the attraction caused by periodicity of nanoparticles in magnetic chains. The discreteness of individual nanoparticles in the nanoneedles is not observed and these nanoneedles interact by their magnetic poles. Since the attraction/repulsion events are predictable, the suspensions of magnetic nanotubes are attractive candidates for active elements in changeable diffraction gratings, filters, and polarizers.
52 citations
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TL;DR: There is, I think, something ethereal about i —the square root of minus one, which seems an odd beast at that time—an intruder hovering on the edge of reality.
Abstract: There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.
Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …
33,785 citations
01 May 1993
TL;DR: Comparing the results to the fastest reported vectorized Cray Y-MP and C90 algorithm shows that the current generation of parallel machines is competitive with conventional vector supercomputers even for small problems.
Abstract: Three parallel algorithms for classical molecular dynamics are presented. The first assigns each processor a fixed subset of atoms; the second assigns each a fixed subset of inter-atomic forces to compute; the third assigns each a fixed spatial region. The algorithms are suitable for molecular dynamics models which can be difficult to parallelize efficiently—those with short-range forces where the neighbors of each atom change rapidly. They can be implemented on any distributed-memory parallel machine which allows for message-passing of data between independently executing processors. The algorithms are tested on a standard Lennard-Jones benchmark problem for system sizes ranging from 500 to 100,000,000 atoms on several parallel supercomputers--the nCUBE 2, Intel iPSC/860 and Paragon, and Cray T3D. Comparing the results to the fastest reported vectorized Cray Y-MP and C90 algorithm shows that the current generation of parallel machines is competitive with conventional vector supercomputers even for small problems. For large problems, the spatial algorithm achieves parallel efficiencies of 90% and a 1840-node Intel Paragon performs up to 165 faster than a single Cray C9O processor. Trade-offs between the three algorithms and guidelines for adapting them to more complex molecular dynamics simulations are also discussed.
29,323 citations
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28,685 citations
28 Jul 2005
TL;DR: PfPMP1)与感染红细胞、树突状组胞以及胎盘的单个或多个受体作用,在黏附及免疫逃避中起关键的作�ly.
Abstract: 抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1(PfPMP1)与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用,在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员,通过启动转录不同的var基因变异体为抗原变异提供了分子基础。
18,940 citations
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TL;DR: This work has shown that combination of pseudo-capacitive nanomaterials, including oxides, nitrides and polymers, with the latest generation of nanostructured lithium electrodes has brought the energy density of electrochemical capacitors closer to that of batteries.
Abstract: Electrochemical capacitors, also called supercapacitors, store energy using either ion adsorption (electrochemical double layer capacitors) or fast surface redox reactions (pseudo-capacitors). They can complement or replace batteries in electrical energy storage and harvesting applications, when high power delivery or uptake is needed. A notable improvement in performance has been achieved through recent advances in understanding charge storage mechanisms and the development of advanced nanostructured materials. The discovery that ion desolvation occurs in pores smaller than the solvated ions has led to higher capacitance for electrochemical double layer capacitors using carbon electrodes with subnanometre pores, and opened the door to designing high-energy density devices using a variety of electrolytes. Combination of pseudo-capacitive nanomaterials, including oxides, nitrides and polymers, with the latest generation of nanostructured lithium electrodes has brought the energy density of electrochemical capacitors closer to that of batteries. The use of carbon nanotubes has further advanced micro-electrochemical capacitors, enabling flexible and adaptable devices to be made. Mathematical modelling and simulation will be the key to success in designing tomorrow's high-energy and high-power devices.
14,213 citations