Wang Q.,CAS Shanghai Institute of Microsystem and Information Technology |
Zhang J.,CAS Shanghai Institute of Microsystem and Information Technology |
Liu W.,Shanghai Nanotechnology Promotion Center |
Xie X.,CAS Shanghai Institute of Microsystem and Information Technology |
Xia B.,CAS Shanghai Institute of Microsystem and Information Technology
Journal of Power Sources | Year: 2017
The Li4Ti5O12 gassing behavior is a critical limitation for applications in lithium-ion batteries. The impact of electrode/electrolyte interface, as well as the underlying mechanisms involved during the gassing process, are still debated. Herein, a quantitative evolution of the internal pressure in 18650-type cylindrical Li4Ti5O12 batteries is investigated using a self-designed pressure testing device. The results indicate that the internal pressure significantly increases during the formation cycle and continues growing during the following cycles. After several charge and discharge cycles, the pressure finally reaches constant. Simultaneously, the formation of the solid electrolyte interphase (SEI) film is also investigated. The results suggest that the initial formed SEI film has a thickness of 24 nm, and is observed to shrink during the following cycles. Furthermore, no apparent increase in thickness accompanying the pressure rising is noticed. These comparative investigations reveal a possible mechanism of the gassing behavior. We suggest that the gassing behavior is associated with side reactions which are determined by the potential of the Li4Ti5O12 electrode, where the active sites of the electrode/electrolyte interface manage the extent of the reaction. © 2017 Elsevier B.V.
Zheng S.,East China University of Science and Technology |
Xu Y.,East China University of Science and Technology |
Zhao C.,East China University of Science and Technology |
Liu H.,University of Wollongong |
And 2 more authors.
Materials Letters | Year: 2012
Li 4Ti 5O 12/C composite anode material was synthesized via solid-state reaction using lithium citrate as lithium source and carbon source. The formation of carbon and its influence on the particle size, morphology and electrochemical properties of the Li 4Ti 5O 12/C composite were investigated in this paper. The results showed that the particles of Li 4Ti 5O 12/C were uniformly distributed with the average particle size of 70 nm and were highly crystalline. The as-prepared sample exhibited high discharge specific capacity and excellent high-rate capability. At 0.2 C, the initial discharge capacity was 176.2 mAh/g. Even at 20 C, the initial discharge capacity could reach 121.1 mAh/g, which retained 106.1 mAh/g after 100 cycles. © 2011 Elsevier B.V. All rights reserved.
Hou Z.,Shanghai JiaoTong University |
Zhou W.,Shanghai Nanotechnology Promotion Center |
Wang Y.,Shanghai JiaoTong University |
Cai B.,Shanghai JiaoTong University
Applied Physics Letters | Year: 2011
We experimentally investigate the characteristics of dielectric barrier discharges in an electrode system with one-dimensional nanostructures of gap size at micrometer scale. Evidence of quasistationary direct current discharges in air has been observed under the applied voltage several times lower than the first ionization potential of O2. The results qualitatively agree with the hypothesis on the ionization mechanism of stepwise inelastic collisions within a metastable pool, which is populated through field excitation and inelastic impact between the neutrals and the nanostructures. © 2011 American Institute of Physics.
Yu F.,Tongji University |
Yu F.,Shanghai JiaoTong University |
Chen J.,Tongji University |
Chen J.,University of Wisconsin - Milwaukee |
And 6 more authors.
Journal of Colloid and Interface Science | Year: 2012
We report a simple and easy method to fabricate magnetic carbon nanotubes (CNTs) by Fenton's reagent method without the addition of any cations. H 2O 2 was added slowly into the FeSO 4 solution mixed with purified CNTs, and the resulting reactants were placed into a quartz tube to undergo heat treatment under a nitrogen/hydrogen flow. Iron oxide (Fe 2O 3) nanoparticles were uniformly dispersed on CNTs without any pretreatment such as strong acid or covalent functionalization processes. The as-produced magnetic CNTs were usedas an adsorbent forremovalof methyl orange (MO) dye fromaqueous solutions. Adsorption experiments indicated that the magnetic CNTs have good adsorption capacity (q e) of MO (28mg/g). The Freundlich isotherm model fitted the experiment databetter than the Langmuirisothermmode. The mean energy of adsorption was calculated as 3.72kJ/mol based on the Dubinin-Radushkevich model, which suggests that theremoval process was dominated by physical adsorption. Kinetic regression results showed that the adsorption kinetics was more accurately represented by a pseudo second-order model. Intra-particle diffusionwasinvolved in the adsorption process, but it was not the only rate-controlling step. More importantly, a new photocatalytic regeneration technology can be enabled by the high nanoscale iron oxide loading (50%). The magnetic CNT adsorbents could be effectively and quickly separated by applying an external magnetic field and regenerated by UV photocatalysis. Therefore, CNTs/λ-Fe 2O 3 hybrid is a promising magnetic nanomaterial for preconcentration and separation of organic pollutants for environmental remediation. © 2012 Elsevier Inc.
Shen J.,East China University of Science and Technology |
Li Y.,East China University of Science and Technology |
Li Y.,Shanghai Nanotechnology Promotion Center |
Zhu Y.,East China University of Science and Technology |
And 5 more authors.
Journal of Materials Chemistry B | Year: 2015
The facile fabrication of Gd-labeled superparamagnetic Fe3O4 nanoparticles (NPs) and fluorescent CuInS2 (CIS) quantum dots conjugated with arginine-glycine-aspartic acid (RGD) peptides has been demonstrated, for tri-mode targeted T1-, T2-weighted magnetic resonance (MR) and fluorescence imaging of pancreatic cancer. The core-shell nanocomposites formed are water-dispersible, stable and biocompatible, as confirmed by MTT assay on BXPC-3 cells. Relaxivity measurements show a T1 relaxivity (r1) of 1.56 mM-1 s-1 and a T2 relaxivity (r2) of 23.22 mM-1 s-1, which enable T1- and T2-weighted MR imaging of cancer cells in vitro and in vivo. The MR imaging data clearly indicate that the multifunctional NPs can specifically target cancer cells with αvβ3 integrin over-expression on the cell surface, through a receptor-mediated delivery pathway. The T1-weighted positive and T2-weighted negative enhancement in the MR imaging significantly improves the diagnosis accuracy, and fluorescence imaging of tumor tissue can assist in clinical surgery. These findings suggest that these multifunctional NPs could be used as a platform for bimodal imaging (both MR and fluorescence) in various biological systems. This journal is © The Royal Society of Chemistry.
Wang J.,Shanghai Nanotechnology Promotion Center |
Kemper T.,University of Florida |
Liang T.,University of Florida |
Sinnott S.B.,University of Florida
Carbon | Year: 2012
Nanostructured carbon materials continue to attract much interest for use in devices and as fillers in composites. Here, classical molecular dynamics simulations are carried out using many-body empirical potentials to contrast the mechanical properties of straight and coiled carbon nanotubes. The specific properties of a coiled carbon nanotube (CCNT) are investigated under compression, tension, re-compression, re-tension and pullout from a polyethylene (PE) matrix. The stress-strain curves, spring constants, and yielding strains under compression and tension are given for each system, and the corresponding reasons for the differences in their behavior are discussed. They indicate that the interaction between a CCNT and a PE matrix is stronger than the corresponding interactions between CNTs and PE. Thus, the results indicate that CCNTs are good potential candidates for lightweight, tough composites. © 2011 Elsevier Ltd. All rights reserved.
Guo L.,CAS Shanghai Institute of Ceramics |
Zhang J.,Red Cross |
He Q.,CAS Shanghai Institute of Ceramics |
Zhang L.,CAS Shanghai Institute of Ceramics |
And 5 more authors.
Chemical Communications | Year: 2010
Millimetre-sized mesoporous carbon spheres (MMCSs) with smooth surface and penetrating mesoporous channels have been successfully prepared by an emulsion-EISA technique, and are found to be a much better bilirubin adsorbent than commercial activated carbon spheres. Hemolysis and coagulation assays of MMCSs indicate that they have negligible hemolysis effect and do not induce blood coagulation. © 2010 The Royal Society of Chemistry.
Liu X.,Shanghai Nanotechnology Promotion Center |
Liu X.,China Jiliang University |
Wang X.,East China Normal University |
Li H.,East China Normal University |
And 6 more authors.
Dalton Transactions | Year: 2015
ZnO-NaSrBO3:Tb3+ (ZNT) composites were successfully synthesized via microwave-assisted reaction of the ZnO precursor with a NaSrBO3:Tb3+ suspension using a microwave synthesis system. The morphology, structure and photocatalytic performance in the degradation of methylene blue (MB) were characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, UV-vis absorption spectroscopy, fluorescence spectrophotometry and electrochemical impedance spectroscopy, respectively. The results show that the ZNT composites exhibit enhanced photocatalytic activity in the degradation of MB with a maximum degradation rate of 97% under visible light irradiation compared with pure ZnO (12%), which is ascribed to the increased light absorption and the reduction of photoelectron-hole pair recombination in ZnO with the introduction of NaSrBO3:Tb3+, as well as the light down-converting effect of NaSrBO3:Tb3+, which facilitates the self-sensitized degradation of MB. This journal is © The Royal Society of Chemistry 2015.
Li J.,East China Normal University |
Liu X.,Shanghai Nanotechnology Promotion Center |
Pan L.,East China Normal University |
Qin W.,East China Normal University |
And 2 more authors.
RSC Advances | Year: 2014
MoS2-reduced graphene oxide (RGO) composites were successfully synthesized via microwave-assisted reduction of graphite oxide in a MoS 2 precursor aqueous solution using a microwave system. The morphology, structure and photocatalytic performance in the degradation of methylene blue (MB) were characterized by scanning electron microscopy, X-ray diffraction, electrochemical impedance spectra and UV-vis absorption spectroscopy, respectively. The results show that the MoS2-RGO composites exhibit enhanced photocatalytic performance in the degradation of MB with a maximum degradation rate of 99% under visible light irradiation for 60 min. This excellent photocatalytic activity is due to the contribution from the reduced electron-hole pair recombination, the enhanced light absorption and the increased dye adsorptivity with the introduction of RGO in the composite. © 2014 The Royal Society of Chemistry.
Chen H.,Shanghai Nanotechnology Promotion Center |
Leng S.,Tongren University
Ceramics International | Year: 2015
Hollow nano-structured hydroxyapatite [Ca10(PO4)6(OH)2, HAp] microspheres were rapidly synthesized via microwave transformation of a sacrificial hard-template of similarly structured calcium carbonate (CaCO3) hollow microspheres in Na3PO4 aqueous solution. Results showed that the microwave process significantly increased transformation efficiency. Pure hollow HAp microspheres could be obtained within ultra-short-period of 30 min via the microwave transformation process, in comparison to over 48 h in the traditional hydrothermal transformation method. These studies suggest that the microwave assisted hard-template transformation process is an effective approach to synthesize HAp with high efficiency. The resulting hollow nano-structured HAp microspheres may have applications in drug-delivery and serve as materials for chemical and environmental applications. © 2014 Elsevier Ltd and Techna Group S.r.l. All rights reserved.