MATERIALS LETTERS
·
2020
·
IF 3.204
Yiming Lei,Jintang Zhou,Zhengjun Yao,Lin Li
Self-assembly porous polyaniline (PANI) microspheres were synthesized via template-free interfacial method at the interface of gallic acid aqueous solution and carbon tetrachloride. The morphology of PANI can be controlled by changing the content of gallic acid. The obtained porous PANI microspheres showed good electromagnetic (EM) wave absorption performance. The maximum reflection loss value of which is −26.5 dB and the effective absorption bandwidth (reflection loss <−10 dB) is about 4.1 GHz. This study is mainly focused on analyzing EM loss based on complex permittivity as the magnetic loss of PANI is neglectable. Further EM analysis indicated that porous PANI microspheres have better impedance matching and attenuation constant, which attributes to the good EM wave absorption. This work can act as a reference for designing PANI microspheres as EM wave absorber by the template-free process.
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL PHYSICS LETTERS
·
2020
·
IF 2.029
Jiaqin Liu,Chen Zhou,Wenzhe Yue,Bo Yan,Yichao Lin,Aisheng Huang
A facile and green template-free hydrothermal method was conducted to controllably synthesize spinel type cobalt oxides (Co 3 O 4 ) with cube, truncated octahedron and octahedron morphologies. The catalytic performance over various shapes of catalysts was investigated towards CO oxidation. Among of them, the Co 3 O 4 cube performs the best catalytic activity, which can even be comparable to those of certain noble metal catalysts. The phenomenon might be ascribed to the synergistic effects of exposed Co 3+ active sites and surface oxygen distribution on the surface of the catalyst. The results may provide significant insights for the fabrication of metal oxide catalysts for CO oxidation .
研究领域:
催化化学
·
材料科学
·
环境化学
·
纳米材料
·
能源化学
✓ 已验证
DOI
高影响因子
NANOTECHNOLOGY
·
2021
·Vol. 32
·期 47
·475708
·
IF 3.874
Qiu-Ping He,Yun Zou,Peng-Fei Wang,Xiao-ming Dou
Silicalite-1 zeolitic membranes have been successfully fabricated on the porous α-Al2O3 support by templated and template-free protocol, respectively, for vapor permeation separation of dichlorobenzene (DCB) isomers. After proving the high quality of the membranes by single gas permeation (He and SF6) performance, the vapor-permeation of DCB isomers over two types of the silicalite-1 membrane was then investigated. The separation results clearly indicated that under the lower partial pressure and higher temperature, the effect of DCB isomer adsorption on the permeance could be kept at a sufficiently low level and sharp selectivity become more important. Thus, high p-DCB selectivity could be achieved. Comparatively, the template-free silicalite-1 zeolite has a much higher p-DCB selectivity due to the relatively fewer inter-crystalline gaps. Under certain separation conditions, the highest selectivity of p-DCB for p-/m-DCB and p-/o-DCB binary systems could reach 165 and 113, respectively.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
MATERIALS CHEMISTRY AND PHYSICS
·
2022
·
IF 4.778
Juguo Dai,Lili Luo,Xiaohong Wang,Long Xia,Hongmei Xie,Chunying Yang,Ruipan Wang,Yiting Xu,Lizong Dai
Nowadays, energy conversion devices have gradually gained attention while vigorously developing clean energy. Carbon materials are promising candidates for supercapacitors , but two issues have plagued the researchers. 1) Does the cation radius in the neutral electrolyte significantly impact the electrochemical performance of carbon materials? 2) How to introduce heteroatoms while constructing hollow structures in carbon spheres. This work proposes a facile template free strategy that uses aniline and pyrrole as nitrogen sources to synthesize carbon sphere precursors. High-temperature carbonization combined with alkali treatment leads to the formation of N-doped hollow porous carbon spheres. Robust wall structure (thickness is about 60–80 nm) and ideal surface structure (the specific surface area is 1079.9 m 2 g −1 ) endow the carbon spheres with excellent electrochemical performance and outstanding cycle stability. The specific capacitance of the carbon spheres in Li 2 SO 4 and Na 2 SO 4 electrolytes under negative working potential (−0.8–0 V) are 378.4 and 367.6 F g −1 , respectively, at a current density of 1 A g −1 . After 5000 cycles, the capacitance retentions are 87.1% and 94.8% in Li 2 SO 4 and Na 2 SO 4 electrolytes. We inferred that the cation radius has a negligible effect on the specific capacitance of carbon materials, but has a more significant effect on the cycling stability and capacitance rate performance. It is hoped that this work can provide a reference for the subsequent construction of N-doped hollow carbon spheres and reasonable selection of electrolytes.
研究领域:
材料科学
·
电化学
·
纳米能源
·
功能材料
·
储能技术
✓ 已验证
DOI
高影响因子
GREEN CHEMISTRY
·
2011
·Vol. 13
·期 10
·2831-2836
·
IF 5.472
Feng Jiang,Shun Wang,Ling Li,Huile Jin,Weiming Zhang,Juanjuan Lin,Tiandi Tang,Jichang Wang
This study develops a simple, rapid electrochemical approach for preparing dendrite-shaped Ag nanomaterials, which are well known as effective SERS substrates. In addition to yielding silver that exhibits a strong enhancement in SERS measurements when tested with 2,2′-dithiodipyridine and ethylenethiourea, this new fabrication method does not require any template, surfactants or supporting electrolyte, making it environment friendly. Analysis illustrates that the as-prepared Ag products are essentially pure silver consisting of abundant {111}-oriented crystallites. These Ag dendrites formed on a commercially available tin-doped indium oxide electrode could also be easily transferred onto other desired surfaces, making their application in SERS measurements more versatile.
研究领域:
分析化学
·
纳米材料学
·
物理化学
·
光谱学
·
生物传感
✓ 已验证
DOI
高影响因子
Journal of Environmental Chemical Engineering
·
2020
·
IF 4.3
Wunengerile Zhang,Yongsheng Bao,Agula Bao
The excessive emission of greenhouse gases such as carbon dioxide (CO 2 ) increases the average surface temperature of the earth through the greenhouse effect. Nitrogen-doped porous carbon materials are considered to be promising solid adsorbents for CO 2 capture. Herein we report a synthesis of nitrogen-doped porous carbon materials using a template-free method. The effects of different nitrogen sources and different carbon sources on the CO 2 adsorption performance of porous carbon materials were studied.The result indicated the ethylenediamine based porous carbon material showed the highest micropore volume and the most surface basic nitrogen atoms , and both lead to good CO 2 adsorption performance. Moreover, it was found that the sample maintained thermal and chemical stability in a long-term (ten cycles) CO 2 adsorption/desorption experiment.
研究领域:
材料科学
·
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY
·
2020
·Vol. 94
·期 2
·416-424
·
IF 2.008
Tian Wei,Du Bin,Shui Anze,Ke Shanjun,Shan Qingliang,He Chao,Ma Juan
In this work, a silica-based mesoporous oxide (SMO) was directly fabricated via a template-free method using the abundant and inexpensive volcanic ash as raw material. By alkali hydrothermal activation and acid hydrothermal etching of volcanic ash, the SMO with large mesopore size (7.94 nm), high specific surface area (459.5 m 2 /g), and total pore volume of 1.05 cm 3 /g was produced. The main ingredient of SMO is amorphous microporous silica. The structural evolutions of the mesoporous materials were revealed by X-ray powder diffraction, scanning electron microscope, Fourier transform infrared spectrometry, N 2 adsorption/desorption, and transmission electron microscopy techniques. The as-prepared SMO possessed excellent adsorption of water vapor as high as 616.0 g/m 2 at the relative humidity ranging from 33 to 75%. This SMO provides a platform for preparing high performance template-freely humidity self-regulating material.
This figure shows that silica-based mesoporous oxide (SMO) quickly adsorbs moisture at RH = 75% and reaches to 616.0 g/m 2 , and then the adsorbed water releases at 33% RH. These results suggest SMO have an excellent humidity self-regulating function in the RH ranging from 33 to 75%.
研究领域:
材料科学
·
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）