CHEMICAL ENGINEERING JOURNAL
·
2021
·
IF 13.273
Yong Chen,Xiaoxiao Zhu,Xinping Wang,Yunpeng Su
A facial and cost-effective protocol preparing multi-hollow silicalite-1 (S-1) zeolite was proposed. That is, treating the parent zeolite with tetrapropylammonium hydroxide (TPAOH) solution at low temperature for a period prior to recrystallization. In this protocol, the geometric structure of the product could be highly controlled from hollow to sponge-like multi-hollow configuration, by modulating the period. It was demonstrated that the key role of this step performed before the recrystallization is to create some deep gullies on the parent zeolite that are necessary for constructing the desired multi-hollow structure. This strategy was also succeeded for fast confining single- or bi-metal nanoparticles in much high dispersion within the multi-hollow S-1 without any protective agent addition. It was proved that this protocol is very effective for dispersing Pt within the sponge-like S-1, even for preparing the Pt@S-1 composite with the Pt content as high as 1.67 wt.%. As a specialty of the protocol, it is that, the protocol always gives desired open mesopores to the product material. The Pt@S-1 and PtSn@S-1 exhibited much higher activity for CO oxidation and propane dehydrogenation than the corresponding conventional catalysts.
研究领域:
材料化学
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纳米催化
·
多孔材料
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化学工程
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工业催化
✓ 已验证
DOI
高影响因子
Applied Sciences-Basel
·
2019
·Vol. 9
·期 5
·956
·
IF 2.217
Huifeng Shi,Xianqiang Liu,Rui Wu,Yijing Zheng,Yonghe Li,Xiaopeng Cheng,Wilhelm Pfleging,Yuefei Zhang
In situ scanning electron microscopy (SEM) offers a good way to investigate the structural evolution during lithiation and delithiation processes. In this paper, the dynamical morphological evolution of 3D-line-structured/unstructured Si/C composite electrodes was observed by in situ SEM. The investigation revealed the microstructural origin of large charge capacity for 3D-line-structured anodes. Based on this proposed mechanism, a coarse optimization of 3D-line-structured anodes was proposed. These results shed light on the unique advantages of using an in situ SEM technique when studying realistic bulk batteries and designing 3D electrode structures.
研究领域:
材料科学
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电化学
·
纳米科技
·
能源存储
·
固体物理
✓ 已验证
DOI
高影响因子
International Journal of Electrochemical Science
·
2023
·
IF 1.5
Haijun Huang,Guangshuai Han,Jingying Xie,Quansheng Zhang
The lithium insertion/extraction properties of silicon oxide (SiO x ) composite electrode are investigated using polyvinylidene fluoride (PVDF), LA132 (which major copolymerization chain is polyacrylonitrile-polyacrylic acid (PAN-PAA)) and polyacrylic acid (PAA). Electrochemical cycling tests show that SiO x electrode with conventional binder PVDF results in rapid capacity fading, while aqueous binders LA132 and PAA remarkably improve the cycle performance of SiO x at a current density of 80 mA·g -1 . SiO x electrode with PAA delivers a reversible capacity up to 1090 mAh·g -1 after 50 cycles. All of the electrodes after 10 cycles exhibiting a huge expansion of surface morphology, and some crevices are observed in SiO x -PVDF electrode. Results of Fourier Transform Infrared Spectroscopy (FTIR) and X-ray diffraction (XRD) show that amorphous or little crystalline grain structure and ester-like bonds are the key factors of adhesion property for binders in SiO x composite electrode. With cycling, impendence of the SiO x electrodes with different binders is increasing severely. In addition, the differential capacity plots are used to explain the capacity fading mechanism, the kinetics of electrode process of SiO x are not affected by applying different binders.
研究领域:
材料科学
·
电化学
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能源存储
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纳米材料
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电池技术
✓ 已验证
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2018
·
IF 4.439
Xiao Huang,Mingqi Li
To improve the cycling stability and rate capability of SiO electrodes, multi-channel and porous SiO@N-doped C (mp-SiO@N-doped C) rods are fabricated by the combination of electrospinning and heat treatment with the assistance of poly(methyl methacrylate) (PMMA). During annealing, in-situ PMMA degradation and gasification lead to the formation of multi-channel structure and more pores. As anodes for lithium ion batteries, the mp-SiO@N-doped C rods exhibit excellent cycling stability. At a current density of 400 mA g −1 , a discharge capacity of 806 mAh g −1 can be kept after 250 cycles, the retention of which is over than 100% versus the initial reversible capacity. Compared with the SiO@N-doped C rods synthesized without the help of PMMA, the mp-SiO@N-doped C rods exhibit more excellent rate capability. The excellent electrochemical performance is attributed to the special structure of the mp-SiO@N-doped C rods. In addition to the conductivity improved by carbon fibers, the multi-channel and porous structures not only make ions/electrons transfer and electrolyte diffusion easier, but also contribute to the structural stability of the electrodes.
研究领域:
材料科学
·
电化学
·
纳米科技
·
能源存储
·
功能材料
✓ 已验证
DOI
高影响因子
SENSORS AND ACTUATORS A-PHYSICAL
·
2021
·
IF 3.407
Wenjia Li,Chang Liu,Dong Liu,Shuda Liu,Tianyan You
The demand for efficient methods to determine mercury ion (Hg 2+ ) is increasing. Herein, we developed a ratiometric fluorescence assay by the coupling of nanozyme and fluorescence resonance energy transfer (FRET) to determine Hg 2+ . Platinum nanoparticles (PtNPs) was synthesized as effective nanozyme to catalyze the oxidation of o-phenylenediamine (OPD) at the presence of hydrogen peroxide (H 2 O 2 ) to produce 2,3-diaminophenazine (DAP). The fluorescence emission of Si quantum dots (QDs) at 414 nm (I 414 ) was observed to be quenched by DAP (emission at 576 nm (I 576 )) via FRET mechanism, whereas Hg 2+ can depress the catalytic activity of PtNPs to generate DAP. Based on this principle, SiQDs/PtNPs/OPD/H 2 O 2 -based ratiometric fluorescence assay was developed that the emission ratio of DAP and SiQDs (I 576 /I 414 ) decreased with a higher concentration of Hg 2+ . Noteworthy, the sensitivity of such system was found to be related with the value of I 576 /I 414 . The developed assay offered a detection range of 20–3000 nM and a detection limit of 10.5 nM. This assay was applied to analyze Yangtze river water, and its reliability has been validated by the standard ICP-MS method. Our work provided an effective and convenient method for Hg 2+ detection.
研究领域:
分析化学
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环境监测
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纳米生物技术
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分子探针
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重金属检测
✓ 已验证
DOI
高影响因子
Catalysts
·
2016
·Vol. 6
·期 12
·181
·
IF 2.964
Jiahuan Yu,An Shen,Yucai Cao,Guanzhong Lu
A highly efficient and stable Pd-diimine@SBA-15 catalyst was successfully prepared by immobilizing Pd onto diimine-functionalized mesoporous silica SBA-15. With the help of diimine functional groups grafted onto the SBA-15, Pd could be anchored on a support with high dispersion. Pd-diimine@SBA-15 catalyst exhibited excellent catalytic performance for the Suzuki coupling reaction of electronically diverse aryl halides and phenylboronic acid under mild conditions with an ultralow amount of Pd (0.05 mol % Pd). When the catalyst amount was increased, it could catalyze the coupling reaction of chlorinated aromatics with phenylboronic acid. Compared with the catalytic performances of Pd/SBA-15 and Pd-diimine@SiO2catalysts, the Pd-diimine@SBA-15 catalyst exhibited higher hydrothermal stability and could be repeatedly used four times without a significant decrease of its catalytic activity.
研究领域:
催化化学
·
材料化学
·
有机合成
·
纳米材料
·
绿色化学
✓ 已验证
DOI
高影响因子
POWDER TECHNOLOGY
·
2012
·
IF 2.08
Xiumei Tai,Jing hong Ma,Zhiping Du,Wanxu Wang,Jianghong Wu
The thermal responsive SiO 2 -PNIPAAm composites were designed and successfully synthesized. The structure, morphology, surface composition and temperature sensitive property in aqueous solution were investigated by Fourier transform infrared spectroscopy (FTIR) and transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), contact angle measurement instrument and dynamic light scatter (DLS). FTIR measurement and N1s and C1s core-level spectrum of XPS illustrate that PNIPAAm is grafted availably. TEM analysis revealed the difference between bare SiO 2 and PNIPAAm-functionalized SiO 2 . The measurements of water contact angle and DLS show that the hydration transition temperature of the thermal responsive SiO 2 -PNIPAAm composites is 304 K. The different grafted PNIPAM content has the obvious effect on the water contact angle measure and DLS for SiO 2.
研究领域:
材料科学
·
高分子化学
·
纳米技术
·
生物医学工程
✓ 已验证
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2011
·
IF 2.13
Xin Tian,Zhengping Dong,Yifan Huang,Jiantai Ma
In this work, molecular logic element modified multifunctional silica nanoparticles having high magnetization have been successfully prepared. These multifunctional nanoparticles were characterized by Fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), Elementary analysis, X-ray powder diffraction (XRD) and Vibrating sample magnetometer (VSM). The characterization datum indicated that the organic ligand was successfully grafted on the surface of the magnetic silica nanoparticles . The fluorescent changes of the hybrid material upon the addition of cations (H + , F − and their mixture) is utilized as an INHIBIT logic gate at the molecular level, using the fluorescence intensity signal as output.
研究领域:
纳米医学
·
生物传感器
·
分子诊断
·
化学生物学
·
智能材料
✓ 已验证
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2019
·Vol. 30
·期 18
·17440-17446
·
IF 2.195
Wang Tianxiong,Meng Xianquan
We try to synthesize In x Ga 1−x Sb nanowires on silicon (100) substrate using InSb and GaSb as source materials and we succeeded. Au film was used as catalysts. The experiment is simple and repeatable. The diameter of the grown nanowires is 60–200 nm and up to 10 microns in length. The grown nanowires have good crystallinity. Due to the doping of indium, we found that the XRD peaks of nanowires were shifted. We have fabricated fully nanostructured device using ultra-long Ag nanowires as electrodes for the I–V characteristic study, and found that the device has photoresponse characteristics and the I–V characteristic curve was asymmetric, we explain that it was due to the asymmetry of this fully nanostructured devices.
研究领域:
材料科学
·
纳米科技
·
半导体物理
·
固体电子学
·
晶体生长
✓ 已验证
DOI
高影响因子
OPTICAL MATERIALS
·
2019
·
IF 2.687
Jiang Wu,Haowen Bai,Wenjie Qu,Guanying Cao,Yanjie Zhang,Jingjie Yu
CsPbBr 3 quantum-dot borosilicate microcrystals and Eu 3+ -doped CsPbBr 3 quantum-dot microcrystals with different concentrations of Eu 3+ are successfully prepared by high temperature melting. The particle morphology of the microcrystals is characterized by scanning electron microscopy (SEM). The fluorescence characteristics are analyzed by fluorescence spectroscopy and CIE chromaticity coordinates . In this research, CsPbBr 3 quantum dots are effectively coated with borosilicate microcrystals to improve the stability of CsPbBr 3 quantum dots while ensuring its strong green emission at 517 nm. The energy transfer from CsPbBr 3 quantum dots to Eu 3+ occurs after doping. When changing the concentration of Eu 3+ , the emission peaks of perovskite broaden and blue shift occurs (517 nm→474 nm). The CIE color coordinate moves from (0.0807, 0.7200) to (0.4537, 0.2724). Therefore, the continuous adjustment of solid perovskite materials from green light to blue light and then to red light region is realized.
研究领域:
材料科学
·
纳米光学
·
无机非金属材料
·
光电子学
·
发光材料
·
固态化学
✓ 已验证
DOI
高影响因子
SURFACE & COATINGS TECHNOLOGY
·
2019
·
IF 3.192
Lu Zhu,Yousen Zhu,Xuanru Ren,Ping Zhang,Jianghao Qiao,Peizhong Feng
MoSi 2 -MoB-ZrO 2 composite powders are one-step synthesized prepared by self-propagating high-temperature synthesis (SHS), which are further utilized to prepare the oxidation protective coatings by spark plasma sintering (SPS) method on molybdenum substrate. Microstructure and properties of the coatings were investigated and determined. Oxidation behavior of the coatings at high temperature was also studied. The results showed that the composite coating is dense and crack-free due to the addition of ZrO 2 , which is beneficial for the decrease of mismatch in coefficient of thermal expansion, and no void exists in the diffusion layer owing to the diffusion of Si, which is inhibited by adding MoB. Compared with the pure MoSi2 coating, the high hardness of the composite coating is enhanced by about 20% while the fracture toughness of the composite coating is improved by about 25%, which makes the occurrence of intergranular fracture , crack deflection and crack bridging. After oxidation at 1400 °C for 80 h, MoSi 2 coating failed while xMoSi 2 -MoB-3ZrO 2 (x = 3, 4, 5) composite coating still kept its protective effect. Only a little substrate is consumed during oxidation and improved oxidation resistance is gained by MoSi 2 -MoB-ZrO 2 composite coating. 3MoSi 2 -MoB-3ZrO 2 coating shows the relatively best oxidation resistance due to the formation of crack-free oxide film on the surface of the coating.
研究领域:
材料科学
·
表面工程
·
高温氧化
·
陶瓷涂层
·
粉末冶金
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry A
·
2021
·Vol. 9
·期 38
·22064-22071
·
IF 12.732
Wenda Zhang,Jie Feng,Fengqi Lu,Alberto J. Fernández-Carrión,Hui Fu,Xiaojun Kuang
Na-doped melilite-type silicate Sr2MgSi2O7 was reported to display high oxide ion conductivity. In this work, through multiple complementary techniques including X-ray diffraction, scanning electron microscopy, transmission electron microscopy, solid-state 29Si and 23Na nuclear magnetic resonance spectroscopy, and DFT calculations of defect formation energies, we found that it is hard to replace Sr with Na in Sr2MgSi2O7, and the Sr2−xNaxMgSi2O7−0.5x compositions formed mixed crystalline Sr2MgSi2O7 and Na-containing glassy phases. AC impedance spectroscopy measurements indicated that the ionic conduction in Sr2−xNaxMgSi2O7−0.5x could be from Na+ ions in the glassy phase, instead of the oxide ions.
研究领域:
材料科学
·
固体离子导体
·
无机非金属材料
·
能源材料
·
电化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）