JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
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2018
·Vol. 29
·期 15
·13180-13187
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IF 2.324
Wang Yan,Wang Yishu,Ma Limin,Han Jing,Guo Fu
Due to the asymmetric structure of Sn unit cell, the electromigration behaviors of Sn based solder joints were significantly depended on the crystal orientation of Sn grain. The present investigation illustrated the effect of Sn grain c -axis on the intermetallic compounds (IMCs) growth under current stressing. The Cu particles reinforced Sn3.5Ag solder joint was selected to obtain various observed surfaces of the sample after 46 days current stressing. The front side, back side, right side and anode side of the sample represented different phenomena, which reflected and proved the importance of c -axis orientation on Cu atomic migration in three-dimension space. Besides, another composite solder joint was polished severe times on the observed surface which was full of IMCs. It showed that the IMCs were covered on the Sn-based solder, and there was crack at the cathode underneath the front surface after 38 days current stressing. The IMC growth behavior would be well understood by systematic study in this work.
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APPLIED SURFACE SCIENCE
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2018
·
IF 4.439
Guodong Du,Yingke Zhou,Xiaohui Tian,Guan Wu,Yakun Xi,Shengyu Zhao
The directional freeze casting technology has received increasing attention as a processing method to fabricate the aligned porous materials due to the advantages of easy operation and free of byproduct. Here, we innovatively applied the directional freezing technology to synthesize the 3D directional porous LiFePO 4 materials. The distinctive 3D directional porous structure of LiFePO 4 is templated from the aligned ice crystals frozen under the temperature gradient in liquid nitrogen . When used as a positive electrode material in lithium-ion batteries, the directional porous LiFePO 4 /C composite exhibits high reversible capacities of 162 mA h g −1 at 0.1 C and 72 mA h g −1 at 10 C, and a high capacity retention of 93.3% after 800 cycles at 1 C. The 3D directional porous LiFePO 4 /C is promising for application in lithium-ion batteries and the synthesis strategy could be potentially extended to prepare other high performance electrode materials.
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ACS Applied Materials & Interfaces
·
2018
·
IF 8.097
Peng Wei,Yanxiang Liu,Zhihao Wang,Yangyang Huang,Yu Jin,Yi Liu,Shixiong Sun,Yuegang Qiu,Jian Peng,Yue Xu,Xueping Sun,Chun Fang,Jiantao Han,Yunhui Huang
NaTi2(PO4)3 (NTP) with a sodium superionic conductor three-dimensional (3D) framework is a promising anode material for sodium-ion batteries (SIBs) because of its suitable potential and stable structure. Although its 3D structure enables high Na-ion diffusivity, low electronic conductivity severely limits NTP’s practical application in SIBs. Herein, we report porous NTP/C nanofibers (NTP/C-NFs) obtained via an electrospinning method. The NTP/C-NFs exhibit a high reversible capacity (120 mA h g–1 at 0.2 C) and a long cycling stability (a capacity retention of ∼93% after 700 cycles at 2 C). Furthermore, sodium-ion full cells and hybrid sodium-ion capacitors have also been successfully assembled, both of which exhibit high-rate capabilities and remarkable cycling stabilities because of the high electronic/ionic conductivity and impressive structural stability of NTP/C-NFs. The results show that the nanoscale-tailored NTP/C-NFs could deliver new insights into the design of high-performing and highly stable anode materials for room-temperature SIBs.
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PubMed
高影响因子
JOURNAL OF CATALYSIS
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2018
·
IF 6.759
Zhao Yang,Wenhan Chen,Jinbao Zheng,Zhiqing Yang,Nuowei Zhang,Chuan-Jian Zhong,Bing Hui Chen
Carbon supported Pt-Ru nano-alloy with multiple reactive sites exhibits unprecedentedly efficient performance in acetone hydrogenation at room temperature. Catalytic properties can be controllably regulated and optimized via performing the specific annealing treatment for the catalyst. The essential correlation between the variations in catalyst’s annealing conditions and the resultant variation in catalytic properties has been explored and discussed as a structure-function relationship. The combination of Pt and Ru sites exhibits enhanced catalytic activity compared with monometallic ones. Larger PtRu alloy particle size favors the rapid C O hydrogenation and the improvement of catalytic selectivity to isopropanol. Isopropyl ether generation is related to the Pt defect sites on the surface, which can be blocked though the catalyst’s oxidation treatment . The presence of surface metal-oxide species is beneficial to the performance enhancement, resulting from the synergetic behavior between metal-oxide sites and metallic sites on respectively activating the reactants. Moreover, 3-pentanone is used as a probe molecule to verify the structure-function relationship of catalytic low-temperature C O hydrogenation on PtRu/C.
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ACS Applied Materials & Interfaces
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2018
·
IF 8.097
Juntao Zhang,Min Li,Xin Liang,Zhongbin Zhuang
Active nonprecious metal-based hydrogen evolution reaction (HER) electrocatalysts are critical for the clean and sustainable generation of hydrogen. Here, we synthesized multishelled FeCo@FeCoP@C hollow spheres by the carbonization and phosphorization of the FeCo-MIL-88 metal-organic framework. Owing to both composition (FeCo mixed phosphide) and morphology (multishelled morphology) effects, the as-obtained FeCo@FeCoP@C exhibits excellent HER performance with a low overpotential of 65 mV to achieve an HER current density of 10 mA cm–2 and high stability in acidic solution. Density functional theory calculations show that the FeCoP have the optimal hydrogen absorption energy than that of FeP and CoP. The carbon shell prevents the oxidation of the phosphides, and the FeCo core provides better conductivity. Our work provides a new method to synthesize multishelled structure catalysts, which has potential applications in the further hydrogen production.
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高影响因子
AUSTRALIAN JOURNAL OF CHEMISTRY
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2018
·Vol. 71
·期 11
·874-881
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IF 1.059
Xue Huang,Jing Zhang,Xiao Zhang,Qing-Ping Wu,Chun-Hui Yan,Xue Huang,Jing Zhang,Xiao Zhang,Qing-Ping Wu,Chun-Hui Yan
Calcined Cu-based metal–organic frameworks impregnated with nickel nitrate catalysts (CuNi@C) were synthesised. X-Ray diffraction, scanning electronic microscopy, energy dispersive X-ray spectrometry, and X-ray photoelectron spectroscopy techniques were applied for the characterisation of the synthesised catalyst, which revealed an octahedral particle shape, rough surface, and metallic copper (Cu, CuO) and nickel (Ni, NiO) particles. CuNi@C was fabricated as a novel peroxymonosulfate (PMS) activator for the oxidative degradation of Acid Orange 7 (AO7) in aqueous media. Results showed that the CuNi@C/PMS system can efficiently degrade nearly 100 % of 0.02 mmol L−1 AO7 within 60 min. In addition, the trapping experiments confirmed the participation of sulfate radicals (SO4•−) and hydroxyl radicals (HO•) as reactive species in the system. Furthermore, the effects of parameters including catalyst and PMS dosages, initial concentration of AO7, and pH were studied. Results showed that the decolourisation efficiency increased with the increase of catalyst dosage, but decreased with the increase of AO7 concentration. The optimal PMS concentration was 0.675 mmol L−1, and initial pH showed no significant effect on the degradation of AO7. Moreover, the CuNi@C could be reused four times with good activity and reusability. Findings revealed that the CuNi@C/PMS system shows potential for degrading contaminants in the environment, due to its catalytic activity and non-negligible adsorption.
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ChemCatChem
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2017
·Vol. 10
·期 2
·415-421
·
IF 4.803
Jianwei Ji,Haiwei Guo,Changzhi Li,Zaojuan Qi,Bo Zhang,Tao Dai,Min Jiang,Chuanqing Ren,Aiqin Wang,Tao Zhang
Graphical Chop up the wood : Tungsten-based bimetallic catalysts exhibit high activity and selectivity in the hydrogenolysis of typical model compounds of the α-O-4 linkage in lignin and deconstruction of lignin feedstock for the production of aromatic chemicals. High yields of C−O cleavage products are obtained without destroying the aromatic rings. Tungsten-based bimetallic catalysts M–W/AC (M=Ru, Pt, and Pd; AC=activated carbon) exhibited high activity and selectivity in the hydrogenolysis of typical α-O-4 model compounds and deconstruction of lignin feedstock for the production of aromatic chemicals. Synergy effect was observed between tungsten and noble-metal species, which on the one hand modulated the hydrogenolysis activity of tungsten and improved the activity of catalyst, and on the other hand suppressed overhydrogenation that avoided the formation of cycloalkanes. The conversion of α-O-4 model compounds with different substituents showed that electronic effects play an important role in stabilizing the reaction intermediates, and the electron-donating methoxy group on the aromatic ring accelerated the hydrogenolysis efficiency. Solvent effect was another factor that determined hydrogenolysis efficiency; dipolar aprotic solvents such as n -hexane provided the high yields of target aromatics. In the conversion of realistic lignins, the bimetallic catalyst showed excellent activity not only in α-O-4 cleavage but also in the hydrogenolysis of other major linkages such as β-O-4 and β−β between aromatic units, so that a high yield of liquid oil was obtained from lignin.
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JOURNAL OF HAZARDOUS MATERIALS
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2016
·
IF 4.836
Anan Wang,Ying Teng,Xuefeng Hu,Longhua Wu,Yujuan Huang,Yongming Luo,Peter Christie
Diphenylarsinic acid (DPAA) is a major contaminant in environments polluted by chemical weapons and abandoned after World Wars I and II and poses high risks to biota but remediation methods for this contaminant are rare. Here, the photodegradtion of DPAA was studied under high-pressure Hg lamp irradiation. DPAA was degraded completely into inorganic arsenic species in 30 min under UV-C irradiation. The photodegradation of DPAA depended mainly on its direct photolysis through excited-state DPAA. By contrast, the generation of 1 O 2 during the photodegradation of DPAA was confirmed by electron paramagnetic resonance (EPR) studies, but 1 O 2 had little effect on the photodegradation of DPAA. Phtotodegradation of DPAA was also studied in soil leachates and groundwater and the photolytic rate of DPAA was controlled by the total organic carbon (TOC) content in soil leachates and by the NO 3 − concentration in groundwater. Finally, studies on the effects of common solutes on the photodegradation of DPAA show that Cl − can increase the photolytic rate of DPAA by prolonging the lifetime of excited-state DPAA. Moreover, NO 3 − , NO 2 − , and humic acid (HA) can decrease the photolytic rate of DPAA by suppressing the production of excited-state DPAA. This research shows the detailed mechanism of DPAA photodegradation and provides a new and effective method for DPAA decontamination.
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Materials
·
2016
·Vol. 9
·期 10
·795
·
IF 2.728
Jinzhu Tang,Qi Ding,Songwei Zhang,Guizhi Wu,Litian Hu
Nanomaterials, such as Graphene, h-BN nanoparticles and MoS2nanotubes, have shown their ability in improving the tribological performance of amorphous carbon (a-C) coatings. In the current study, the effectiveness of ZrO2nanoparticles (ZrO2-NPs) in lubricating the self-mated nonhydrogenated a-C contacts was investigated in boundary lubrication regime. The results showed that 13% less friction and 50% less wear compared to the base oil were achieved by employing ZrO2-NPs in the base oil in self-mated a-C contacts. Via analyzing the ZrO2-NPs and the worn a-C surface after tests, it was found that the improved lubrication by ZrO2-NPs was based on “polishing effects”, which is a new phenomenon observed between a-C and nanoparticles. Under the “polishing effect”, micro-plateaus with extremely smooth surface and uniform height were produced on the analyzed a-C surface. The resulting topography of the a-C coating is suitable for ZrO2-NPs to act as nano-bearings between rubbing surfaces. Especially, the ZrO2-NPs exhibited excellent mechanical and chemical stability, even under the severe service condition, suggesting that the combination of nonhydrogenated a-C coating with ZrO2-NPs is an effective, long lasting and environment-friendly lubrication solution.Keywords:amorphous carbon coating;ZrO2nanoparticles;friction coefficient;wear;polishing effect
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CONSTRUCTION AND BUILDING MATERIALS
·
2017
·
IF 3.169
Jinfeng Sun,Hu Shi,Binbin Qian,Zhiqiang Xu,Weifeng Li,Xiaodong Shen
This work investigates the influence of synthetic C-S-H/polycarboxylate(PCE) nanocomposites (CPNs) on the hydration and properties of hydrated cement pastes. HPEG-PCE copolymers exhibiting side chain length of 45 ethylene oxide (EO) units was utilized to synthesize CPNs by precipitating C-S-H from Na 2 SiO 3 and Ca(NO 3 ) 2 in the PCE solution. A Box-Behnken Design (BBD) for the Response Surface Methodology (RSM) was employed to statistically optimize the sizes of the resultant. The prepared CPNs were characterized by particle size distribution (PSD), X-ray diffraction (XRD), Fourier transform infrared spectra (FT-IR) and thermo gravimetric/derivative thermo gravimetric (TG/DTG) analyses. The influence of CPNs on the hydration properties of cement were assessed and discussed in terms of hydration kinetics, mechanical properties, phase composition and pore structure analysis. The experimental results showed that the optimum synthetic parameters, an experimental temperature of 30.1 °C, reactant flow velocity of 0.63 ml/min and initial volume of PCE solution of 28.5 ml, produced CPNs with a minimum size of 329.12 nm. It was demonstrated that PCE polymers were either grafted on the surface or partially intercalated in the interlayer regions of C-S-H, and their introduction also increased the distance between C-S-H interlayers. Cement hydration was significantly promoted as a result of an increased heat release, even at low CPNs content. The early compressive strength of the mortar significantly improved with increasing CPNs content due to the accelerated cement hydration of the CPNs: the 0.6 wt.% CPNs content improved the compressive strength by 18.97%. Moreover, the inclusion of CPNs is advantageous for pore modification: the total porosity decreased by 25.77% after 3 days. Finally, phase composition analysis confirmed that no new crystalline phase was produced upon CPNs addition.
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ACS Sustainable Chemistry & Engineering
·
2017
·
IF 5.951
Linglin Zhou,Guilong Zhang,Jie Tian,Dongfang Wang,Dongqing Cai,Zhengyan Wu
Core–shell magnetic Fe3O4@C nanospheres functionalized with active chemical groups were synthesized via a one-step template-free solvothermal process and employed to remove hexavalent chromium (Cr(VI)) in aqueous media. The structure of Fe3O4@C nanoparticles could be effectively adjusted by the concentration of precursor. The Fe3O4 core possessed a high magnetism for the convenient separation of Fe3O4@C from aqueous solution, and high porosity and abundant functional groups (−OH, −COOH, and C═C) of carbon layer contributed to a superior performance on Cr(VI) removal. Therein, Cr(VI) ions could be efficiently adsorbed into the carbon layer and reduced to trivalent chromium (Cr(III)) mainly by C═C, and the resulting Cr(III) were chelated by the −COOH group. Noteworthy, the carbon layer thickness, pore size, and amount of chemical groups significantly increased with the increase of Fe3O4@C particle size resulting in a rising removal efficiency on Cr(VI). This study provides a promising approach for removing Cr(VI) and may have a huge application potential.
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JOURNAL OF PHASE EQUILIBRIA AND DIFFUSION
·
2017
·Vol. 38
·期 1
·30-36
·
IF 0.938
Sun W. Z.,Cheng J. G.,Huang Z. K.,Jiang Y.,Wu L. E.,Liu L. M.
The present work determined the phase relations in Si-Al-M-O-C (M = Zr, Mg) systems, involving SiC-Al 2 O 3 -ZrO 2 , SiC-Al 2 O 3 -MgO, SiC-SiO 2 -Al 2 O 3 -ZrO 2 and SiC-SiO 2 -Al 2 O 3 -MgO systems by XRD phase analyses of the solid-state reacted samples from powder mixtures of SiC, Al 2 O 3 , ZrO 2 , MgO and SiO 2 . Within these systems, SiC was respectively compatible with other neighboring phases, forming a set of four-phase compatibility tetrahedrons. The subsolidus phase diagrams of the SiC-SiO 2 -Al 2 O 3 -ZrO 2 and SiC-SiO 2 -Al 2 O 3 -MgO quaternary systems were presented.
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危险品化学品经营许可证（带存储）