The University of Tokyo · 재료과학
Rong Xiang 교수의 연구실은 리튬-황 배터리의 고성능화를 위한 다기능 고분자 바인더 개발과 동시에, 단일벽 나노튜브(SWCNT)의 고굴절성 합성 및 성장 메커니즘 규명을 핵심 연구 분야로 삼고 있습니다. 특히 촉매 구조의 동적 관찰을 통해 나노튜브 성장 메커니즘을 실시간으로 규명하고, 기질 확산과 촉매 활성 유지 전략을 제시합니다. 이는 에너지 저장 소자 및 나노전자 소자 응용을 위한 고성능 나노소재 설계에 기여합니다.
표시된 성과는 수집된 데이터 기준으로 산출되며, 일부 차이가 있을 수 있습니다.
Abstract Lithium–sulfur (Li–S) batteries have received tremendous attention due to their superior theoretical energy density of 2600 Wh kg −1 , as well as the abundance of sulfur resources and its environmental friendliness. Polymer binders as an indispensable component in cathodes play a critical role in maintaining the structural integrity and stability of electrodes. Additionally, multifunctional polymer binders have been involved in Li–S batteries to benefit electrochemical performance by mi
Feedstock and byproduct diffusion in the root growth of aligned carbon nanotube arrays is discussed. A non-dimensional modulus is proposed to differentiate catalyst-poisoning controlled growth deceleration from one which is diffusion controlled. It is found that, at the current stage, aligned multiwalled carbon nanotube arrays are usually free of feedstock diffusion resistance while single-walled carbon nanotube arrays are already suffering from a strong diffusion resistance. The method presente
Recently, W-based catalysts have provided a promising route to synthesize single-walled carbon nanotubes (SWCNTs) with specific chirality, but the mechanism of the growth selectivity is vaguely understood. We propose a strategy to identify the atomic structure as well as the structure evolution of the Co-W-C ternary SWCNT catalyst. The key is to use a thin SiO<sub>2</sub> film as the catalyst support and observation window. As the catalyst is uniformly prepared on this SiO<sub>2</sub> film and d
Addition of only 1% acetylene into ethanol was found to enhance the growth rate of single-walled carbon nanotubes (SWNTs) by up to 10-fold. This accelerated growth, however, only occurred in the presence of ethanol, whereas pure acetylene at the same partial pressure resulted in negligible growth and quickly deactivated the catalyst. The dormant catalyst could be revived by reintroduction of ethanol, indicating that catalyst deactivation is divided into reversible and irreversible stages. Since
By sequential feeding of catalyst materials (see figure) it is revealed that the active growth sites are at the bottom of carbon nanotubes (CNTs), and that catalyst particles are constantly encapsulated into the CNTs (see figure). This gives a better insight into the mechanism of CNT formation and on ways to control the growth process. CNTs encapsulating different materials should enable the study of their electronic or magnetic properties, with potential applications as building blocks for nano
Membrane proteins play a central role in the interaction of the cell with its environment and in the function of subcellular organelles. The current study focused on developing a better understanding of the membrane proteome of two well-characterized breast cancer cell lines. Membranes from osmotically lysed BT474 and MCF7 cells were treated with cyanogen bromide followed by a combination of trypsin and Staphylococcus V8 protease to obtain hydrophilic peptides from membrane proteins. The complex
Synthesis of single-walled carbon nanotubes (SWNTs) with well-defined atomic arrangements has been widely recognized in the past few decades as the biggest challenge in the SWNT community, and has become a bottleneck for the application of SWNTs in nano-electronics. Here, we report a selective synthesis of (12, 6) SWNTs with an enrichment of 50%-70% by chemical vapor deposition (CVD) using sputtered Co-W as a catalyst. This is achieved under much milder reduction and growth conditions than those
1D van der Waals heterostructures based on carbon nanotube templates are raising a lot of excitement due to the possibility of creating new optical and electronic properties, by either confining molecules inside their hollow core or by adding layers on the outside of the nanotube. In contrast to their 2D analogs, where the number of layers, atomic type and relative orientation of the constituting layers are the main parameters defining physical properties, 1D heterostructures provide an addition
We demonstrate wide-range diameter modulation of vertically aligned single-walled carbon nanotubes (SWNTs) using a wet chemistry prepared catalyst. In order to ensure compatibility to electronic applications, the current minimum mean diameter of 2 nm for vertically aligned SWNTs is challenged. The mean diameter is decreased to about 1.4 nm by reducing Co catalyst concentrations to 1/100 or by increasing Mo catalyst concentrations by five times. We also propose a novel spectral analysis method th
A novel strategy for the large scale, continuous production of aligned carbon nanotube arrays using millimeter‐diameter spheres as growth substrates is reported (see figure and cover). The present technique is more productive than the conventional process on flat wafers because of the higher available growth surface and the good fluidity of the spherical substrates. It can be adapted for the industrial production and application of aligned carbon nanotube arrays with lengths of up to one millime
The mechanism of separating charged species by capillary electrochromatography (CEC) was modeled with the conditions of ideal/linear chromatography by using a simple random walk. The most novel aspect of the work rests with the assumption that in sufficiently high electric field ionized sample components can also migrate in the adsorbed state on the ionized surface of the stationary phase. This feature of CEC leads to the introduction of three dimensionless parameters: alpha, reduced mobility of
We recently synthesized one-dimensional (1D) van der Waals heterostructures in which different atomic layers (e.g., boron nitride or molybdenum disulfide) seamlessly wrap around a single-walled carbon nanotube (SWCNT) and form a coaxial, crystalized heteronanotube. The growth process of 1D heterostructure is unconventional-different crystals need to nucleate on a highly curved surface and extend nanotubes shell by shell-so understanding the formation mechanism is of fundamental research interest