scispace - formally typeset
Search or ask a question
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.


Papers
More filters
Journal ArticleDOI
TL;DR: In this paper, Nb4C3Tx MXene nanosheets are delaminated and a freestanding film with 1.77 nm interlayer spacing is obtained, which is larger than that of most previous MXenes.
Abstract: MXenes derived from 413 MAX phases are rarely studied but they have the potential to have superior electrical and mechanical properties thanks to a thicker monolayer (four layers of transition metal and three layers of carbon or nitrogen). In this paper, Nb4C3Tx MXene nanosheets are delaminated and freestanding film with 1.77 nm interlayer spacing is obtained, which is larger than that of most previous MXenes. When Nb4C3Tx freestanding films are tested as supercapacitors electrodes, Nb4C3Tx shows high volumetric capacitance, 1075, 687, and 506 F cm−3 in 1 m H2SO4, 1 m KOH, and 1 m MgSO4, respectively, at the scan rate of 5 mV s−1. An in situ X-ray diffraction technique is used to study the structural changes during the electrochemical charging in 1 m H2SO4 and 1 m MgSO4. There is almost no change in the 21 Å interlayer spacing during the cycling, because the space between the MXene layers is sufficient to accommodate the insertion and deinsertion of cations. This can lead to stable performance of Nb4C3Tx MXene energy storage devices.

80 citations

Journal ArticleDOI
21 Jun 2018
TL;DR: A nanochanneled Ti3C2Tx MXene membrane that enables an efficient controlled rejection/permeation of inorganic ions and organic dye molecules under applied electrical potential is reported.
Abstract: We report a nanochanneled Ti3C2Tx MXene membrane that enables an efficient controlled rejection/permeation of inorganic ions and organic dye molecules under applied electrical potential. When a negative electrical potential (−0.6 V) is applied to the Ti3C2Tx MXene membrane under only osmotic pressure, the rejection of inorganic salt (NaCl or MgSO4) through the membrane is enhanced. In contrast, applying a positive potential inhibits the rejection through electrostatic repulsion between charged MXene layers and inorganic cations in solution. The rejection rates of Ti3C2Tx membranes are also tested in a flow-through system. MXene membranes as thin as 100 nm show a high rejection rate above 97.9 ± 1.0% for methylene blue dye molecules. Similar to inorganic salts, application of negative or positive voltages increases and decreases, respectively, the transport of molecules through Ti3C2Tx membranes. The voltage gated rejection through electronically conductive membranes is demonstrated as a promising alternat...

80 citations

Journal ArticleDOI
TL;DR: In this article, Ramaman spectroscopy and transmission electron microscopy are used to investigate the temperature effects on the stability of metastable silicon phases (Si-III and Si-XII) produced by nanoindentation.
Abstract: Raman spectroscopy and transmission electron microscopy are used to investigate the temperature effects on the stability of metastable silicon phases (Si–III and Si–XII) produced by nanoindentation. It is found that the thickness of the specimen beneath the residual imprint plays an important role in the phase transformation sequence during heating up to 200 °C. Amorphization is preferred in nanoindents located in thin and loosely constrained areas; formation of Si–IV from Si–III/Si–XII is observed in the residual imprints located in the areas with an intermediate thickness; and the formation of an unidentified “Si–XIII” structure, which precedes the formation of Si–IV, is observed in nanoindents constrained by the bulk wafer. The phase transformation sequence in the indented samples under annealing is established as follows: Si–XII→Si–III→Si–XIII (thick sample only)→a-Si or Si–IV→nanocrystalline Si–I→Si–I.

80 citations

Journal ArticleDOI
TL;DR: In this paper, nanoporous carbons obtained by selective leaching of Ti and Al from Ti2AlC, as well as B from B4C, were investigated as electrode materials in electric double-layer capacitors.
Abstract: Nanoporous carbons obtained by selective leaching of Ti and Al from Ti2AlC, as well as B from B4C, were investigated as electrode materials in electric double-layer capacitors. Cyclic voltammetry tests were conducted in 1 M H2SO4 from 0-250 mV on carbons synthesized at 600, 800, 1000, and 1200°C. Results show that the structure and pore sizes can be tailored and that the optimal synthesis temperature is 1000°C. Specific capacitances for Ti2AlC CDCs and B4C CDCs were 175 and 147 F/g, respectively, compared to multiwall carbon nanotubes and two types of activated carbon, measured herein to be 15, 52, and 125 F/g, respectively. © 2005 The Electrochemical Society. @DOI: 10.1149/1.1921134# All rights reserved.

78 citations


Cited by
More filters
Journal ArticleDOI

[...]

08 Dec 2001-BMJ
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

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

Journal ArticleDOI
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