http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
- 中文 을 입력하시려면 zhongwen을 입력하시고 space를누르시면됩니다.
- 北京 을 입력하시려면 beijing을 입력하시고 space를 누르시면 됩니다.
RISS 인기검색어
- 검색키워드
- 저자 : Yuhang Su (검색결과 2 건)
- 무료
- 기관 내 무료
- 유료
-
Su, Dawei,Han Seo, Dong,Ju, Yuhang,Han, ZhaoJun,Ostrikov, Kostya,Dou, Shixue,Ahn, Hyo-Jun,Peng, Zhangquan,Wang, Guoxiu Nature Publishing Group 2016 NPG Asia Materials Vol.8 No.-
<P>The electrochemical performance of lithium-oxygen (Li-O-2) batteries can be markedly improved through designing the architecture of cathode electrodes with sufficient spaces to facilitate the diffusion of oxygen and accommodate the discharge products, and optimizing the cathode catalyst to promote the oxygen reduction reaction and oxygen evolution reaction (OER). Herein, we report the synthesis of ruthenium (Ru) nanocrystal-decorated vertically aligned graphene nanosheets (VGNS) grown on nickel (Ni) foam. As an effective binder-free cathode catalyst for Li-O-2 batteries, the Ru-decorated VGNS@Ni foam can significantly reduce the charge overpotential via the effects on the OER and achieve high specific capacity, leading to an enhanced electrochemical performance. The Ru-decorated VGNS@Ni foam electrode has demonstrated low charge overpotential of similar to 0.45 V and high reversible capacity of 23 864 mAh g(-1) at the current density of 200 mA g(-1), which can be maintained for 50 cycles under full charge and discharge testing condition in the voltage range of 2.0-4.2 V. Furthermore, Ru nanocrystal decorated VGNS@Ni foam can be cycled for more than 200 cycles with a low overpotential of 0.23 V under the capacity curtained to be 1000 mAh g(-1) at a current density of 200 mA g-1. Ru-decorated VGNS@Ni foam electrodes have also achieved excellent high rate and long cyclability performance. This superior electrochemical performance should be ascribed to the unique three-dimensional porous nanoarchitecture of the VGNS@Ni foam electrodes, which provide sufficient pores for the diffusion of oxygen and storage of the discharge product (Li2O2), and the effective catalytic effect of Ru nanocrystals on the OER, respectively. Ex situ field emission scanning electron microscopy, X-ray diffraction, Raman and Fourier transform infrared measurements revealed that Ru-decorated VGNS@Ni foam can effectively decompose the discharge product Li2O2, facilitate the OER and lead to a high round-trip efficiency. Therefore, Ru-decorated VGNS@Ni foam is a promising cathode catalyst for rechargeable Li-O-2 batteries with low charge overpotential, long cycle life and high specific capacity.</P>
-
Qingna Xu,Tongchao Ji,Qingfeng Tian,Yuhang Su,Liyong Niu,Xiaohong Li,Zhijun Zhang 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2018 NANO Vol.13 No.12
A series of silica surface-capped with hexamethyldisilazane (denoted as H-SiO2) were prepared by liquid-phase in-situ surface-modification method. The as-obtained H-SiO2 was incorporated into acrylic amino (AA) baking paint to obtain AA/H-SiO2 composite extinction paints and/or coatings. N2 adsorption–desorption tests were conducted to determine the specific surface area as well as pore size and pore volume of H-SiO2. Moreover, the effects of H-SiO2 matting agents on the physical properties of AA paint as well as the gloss and transmittance of AA-based composite extinction coatings were investigated. Results show that H-SiO2 matting agents possess a large specific surface area and pore volume than previously reported silica obtained by liquid-phase method. Besides, they have better dispersibility in AA baking paint than the unmodified silica. Particularly, H-SiO2 with a silica particle size of 6.7 μm and the dosage of 4% (mass fraction) provides an extinction rate of 95.2% and a transmittance of 79.3% for the AA-based composite extinction coating, showing advantages over OK520, a conventional silica matting agent. Along with the increase in the silica particle size, H-SiO2 matting agents cause a certain degree of increase in the viscosity of AA paint as well as a noticeable decrease in the gloss of the AA-based composite extinction coating, but they have insignificant effects on the hardness and adhesion to substrate of the AA-based composite coatings. This means that H-SiO2 matting agents could be well applicable to preparing low-viscosity and low-gloss AA-based matte coatings.
연관 검색어 추천
이 검색어로 많이 본 자료
활용도 높은 자료
