Nano Energy
·
2016
·
IF 11.553
Zhaoqiang Li,Caixia Li,Xiaoli Ge,Jingyun Ma,Zhiwei Zhang,Qun Li,Chengxiang Wang,Longwei Yin
Reduced graphene oxide (RGO) wrapped metal-organic frameworks (MOFs) derived cobalt doped porous carbon polyhedrons synthesized via a carbonization process, are for the first time used for sulfur immobilizers (RGO/C–Co-S) as cathodes for high performance lithium-sulfur (Li–S) batteries. The RGO/C–Co–S cathode exhibits greatly improved electrochemical performance, showing excellent specific capacity of 949 mAh g −1 at 300th cycle at a current density 0.3 A g −1 , displaying enhanced rate capability with specific capacity of 772, 704 and 606 mAh g −1 at current density of 0.5, 1 and 2 A g −1 , respectively. The synergetic effect of MOFs-derived porous carbon, homogeneously distributed Co nanoparticles and RGO nanosheets simultaneously contributes to the confinement of sulfur species. The presence of abundant mesopores and micropores is conducive to immobilize large amounts of S species. The homogenously inlaid ultrafine Co nanoparticles can further immobilize sulfur by chemical interactions between Co and S/polysulfides. The RGO nanosheets tightly wrapped on carbon hosts act as barrier layers to prevent polysulfides from diffusing out of the matrix, further suppressing shuttle effect. The porous structure and the RGO can effectively alleviate the volume changes resulted from charge–discharge process. This design strategy can be inspiring for MOF-derived materials in energy storage applications .
研究领域:
材料科学
·
电化学
·
能源存储
·
纳米材料
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电池技术
✓ 已验证
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2020
·Vol. 44
·期 15
·6003-6009
·
IF 3.288
Yuhang Jiang,Qiuwan Shen,Shian Li,Guogang Yang,Naibao Huang
B-site cobalt-doped perovskite oxide BaNiO3 oxygen sorbents have been synthesized by an EDTA sol–gel method and further applied for producing oxygen. BaCoxNi1−xO3−δ oxygen sorbents were characterized by scanning electron microscopy (SEM) and cyclic oxygen adsorption/desorption experiments. Results showed that BaCo0.6Ni0.4O3−δ features higher production amounts of oxygen among the candidates. The operating factors of oxygen releasing performance were investigated in detail including adsorption temperature, desorption temperature, adsorption time, CO2 flow rate and CO2 partial pressure. It was concluded that the temperature and CO2 flow rate are the main reasons affecting the performance of perovskite oxygen sorbents. The optimal operating parameters of oxygen releasing performance for BaCo0.6Ni0.4O3−δ were as follows: adsorption temperature was 850 °C, desorption temperature was 850 °C, air adsorption time was 30 min, CO2 flow was 200 ml min−1 and the ratio of CO2/N2 was 100 : 0. The oxygen production amount of BaCo0.6Ni0.4O3−δ was 49.5 mg g−1 under the optimal reaction conditions. Finally, multiple cycles demonstrated that BaCo0.6Ni0.4O3−δ displays higher stability and regeneration capacity, which is the key factor providing a stable O2/CO2 gas stream for oxyfuel combustion application.
研究领域:
材料科学
·
无机化学
·
能源化学
·
化学工程
·
功能材料
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry A
·
2017
·Vol. 5
·期 27
·14278-14285
·
IF 8.867
Haibo Tang,Xinlong Tian,Junming Luo,Jianhuang Zeng,Yingwei Li,Huiyu Song,Shijun Liao
Transition metal nitrides have recently attracted significant interest as electrocatalysts for the oxygen reduction reaction (ORR) owing to their low electrical resistance and good corrosion resistance. In this paper, we describe the preparation of a Nb-based binary nitride material with a porous nanogrid morphology/structure. The catalyst exhibited good catalytic activity and high stability towards oxygen reduction. We also intensively investigated the effect that doping with a second transition metal had on the performance of the catalyst. We found that the ORR activity of NbN could be enhanced significantly by enriching the d electrons of Nb through doping with a second transition metal, and that doping with cobalt resulted in the best improvement. Our optimal catalyst, Nb0.95Co0.05N, had an ORR activity ∼4.6 times that of NbN (current density @ 0.6 V vs. the RHE). XPS results revealed that Co doping increased the proportion of Nb in a low-valence state, which may be one of the most important reasons for the enhanced performance. Another important reason is the high surface area resulting from the porous nanogrid morphology. As transition metal doping is an attractive way to enhance the activity of nitride catalysts, our work may provide an effective pathway to achieve this.
研究领域:
材料科学
·
电化学
·
纳米科技
·
催化化学
·
能源材料
✓ 已验证
DOI
高影响因子
APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
·
2019
·Vol. 125
·期 3
·158
·
IF 1.784
Gao Dong-Sheng,Gao Xiang-Dong,Wu Yong-Qing,Zhang Tong-Tong,Yang Jing-Nan,Li Xiao-Min
Co doped BaSnO 3 films [BaSn 1 − x Co x O 3 (0 ≤ x ≤ 0.50), i.e., BSCO] have been grown on MgO single-crystal substrates via pulsed laser deposition. Effects of the Co-doping level on the crystallinity, the microstructure, and optical properties of the BSCO films are investigated. All the BSCO films are of high crystallinity and grown epitaxially on MgO substrates. The lattice parameter of the (200) plane drops linearly with the increase of the ‘ x ’ value. The Co doping is found to increase the film roughness and the grain size, and a RMS roughness of 8.33 nm and grain size up to 100 nm are observed in the film with x = 0.50. The low Co-doping level ( x = 0.05, 0.1) has slight anti-reflection effects on the incident visible light, and the Co-doping level higher than 0.2 reduces the optical transmittance significantly. The optical bandgap shows a first-rising then falling trend with the increase of the Co content, and the lowest bandgap of 1.94 eV is realized in the BSCO film with x = 0.50.
研究领域:
材料科学
·
凝聚态物理
·
薄膜制备
·
光学材料
·
功能氧化物
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）