Aging property for LiFePO<Subscript>4</Subscript>/graphite cell with different temperature and DODs

In this paper, we fabricated 1.7 A h soft-packed cells using commercial-grade LiFePO₄ and manmade graphite as the active materials for the cathode and anode, respectively. It has been shown that the cycle performances of assembled soft-packed full-cell were still temperature-dependent. An accelerated mechanism of the operating temperature to reformation/repairing of SEI layer have been established, which greatly consumes active lithium during cycling, therefore causes fast capacity loss at elevated temperatures. At same time, cycle property for LiFePO₄/graphite cell with different depth of discharge (DOD) levels and ranges. It has been shown that DOD level has very little effect on capacity fade for cell lifecycle; but for DOD range, obvious influence was observed on capacity fade, which is due to the sensitivity of SOC during the storage of the cell.     

Room temperature synthesis of water-repellent polystyrene nanocomposite coating

A stable superhydrophobic polystyrene nanocomposite coating was fabricated by means of a very simple and easy method. The coating was characterized by scanning electron microscopy and X-ray photoelectron spectrum. The wettability of the products was also investigated. By adding the surface-modified SiO₂ nanoparticles, the wettability of the coating changed to water-repellent superhydrophobic, not only for pure water, but also for a wide pH range of corrosive liquids. The influence of the drying temperature and SiO₂ content on the wettability of the nanocomposite coating was also investigated. It was found that both factors had little or no significant effect on the wetting behavior of the coating surface.     

Studies on the electrochemiluminescent behavior of luminol on indium tin oxide (ITO) glass

The electrochemiluminescence (ECL) of luminol on indium tin oxide (ITO) glass was high even under a low potential around 0.4-0.5 V, which was quite different from other electrodes such as platinum. ITO nanoparticles were synthesized and used in the research on ITO glass in the ECL process. A static interaction between ITO and luminol is confirmed from UV-vis and fluorescence spectra. Then the ECL enhancement can be supposed to originate from the adsorption of luminol on ITO, which facilitated luminol’s oxidization to the excited state, giving out ECL. On the other hand, ITO can catalyze the generation of reactive oxygen species (ROSs), similar to some other nanomaterials, which also favored the ECL enhancement of luminol.     

Facile fabrication of pomponlike microarchitectures of lanthanum molybdate via an ultrasound route

Pomponlike La₂(MoO₄)₃ microstructures assembled with single-crystalline nanoflakes have been facilely fabricated via a surfactant-assisted ultrasound route for the first time. Various synthesis conditions were examined, such as the surfactant concentration, the molecular structure of surfactants, and the pH value. The obtained pomponlike microstructures were characterized by X-ray diffraction (XRD), (field-emission) scanning electron microscopy [(FE)SEM], transmission electron microscopy (TEM), and nitrogen adsorption/desorption isotherms. It has been revealed that a minimum concentration of sodium dodecylsulfate (SDS) was required for the formation of pomponlike La₂(MoO₄)₃ microstructures. When the SDS concentration is above 0.02 mol L⁻¹, the pomponlike microstructures become more perfect, and the size is also increased with the increasing SDS concentration. Under the same sonication, similar pomponlike microstructures were obtained when a cationic surfactant, cetyltrimethyl ammonium bromide (CTAB), was used instead of the anionic surfactant SDS, indicating that the hydrophobic alkyl chains are an important factor for the formation of the pomponlike La₂(MoO₄)₃ microstructures. It is also found that the pomponlike La₂(MoO₄)₃ microstructures can only be obtained within an optimal pH range of 8.0–9.0 under sonication. Based on TEM, Fourier transform infrared spectroscopy (FT-IR) and solubilization experiment, a formation mechanism of pomponlike La₂(MoO₄)₃ microstructures was proposed, in which the collaborative action of surfactants and sonication plays a key role. Furthermore, the porosity of the pomponlike La₂(MoO₄)₃ microstructures were discussed.     

Roles of γ-Fe2O3 in fly ash for mercury removal: Results of density functional theory study

First-principle calculations based on density function theory (DFT) are used to clarify the roles of γ-Fe₂O₃ in fly ash for removing mercury from coal-fired flue gases. In this study, the structure of key surface of γ-Fe₂O₃ is modeled and spin-polarized periodic boundary conditions with the partial relaxation of atom positions are employed. Binding energies of Hg on γ-Fe₂O₃ (0 0 1) perfect and defective surfaces are calculated for different adsorption sites and the potential adsorption sites are predicted. Additionally, electronic structure is examined to better understand the binding mechanism. It is found that mercury is preferably adsorbed on the bridge site of γ-Fe₂O₃ (0 0 1) perfect surface, with binding energy of −54.3 kJ/mol. The much stronger binding occurs at oxygen vacancy surface with binding energy of −134.6 kJ/mol. The calculations also show that the formation of hybridized orbital between Hg and Fe atom of γ-Fe₂O₃ (0 0 1) is responsible for the relatively strong interaction of mercury with the solid surface, which suggests that the presently described processes are all noncatalytic in nature. However, this is a reflection more of mercury's amalgamation ability.     

Experimental Study of a Closed System in the Chlorine Dioxide–Iodine–Ethyl Acetoacetate–Sulfuric Acid Oscillation Reaction by UV-vis and Online FTIR Spectrophotometric Methods

The appearance of oscillations for the closed system ClO₂–I₂–ethyl acetoacetate depends critically on the pH in the absence of sulfuric acid, and was investigated by determining changes in the absorbance of I₃ ^-\mathrm{I}_{3}^{ -} with reaction time at the wavelength 280 nm. The pH should be 2.2–3.8 for this reaction. The initial concentrations of ethyl acetoacetate, chlorine dioxide, iodine and sulfuric acid have great influences on the oscillations observed at wavelengths of 280 nm or 350 nm. The oscillations at 280 nm occur as long as the reactants are mixed. However, at 350 nm the oscillation is preceded by a pre-oscillatory or induction period. The oscillation curve is more regular and smooth at 350 nm than that at 280 nm. The amplitude and the number of oscillations are associated with the initial concentration of each reactant. (1) The higher the initial concentration of ethyl acetoacetate, the greater is the amplitude while the number of oscillations becomes smaller. The amplitude is small at the beginning stage but increases with reaction time. An opposite influence exists for chlorine dioxide. Finally, the oscillation suddenly ceases. (2) When the initial concentration of iodine is higher, the amplitude is small at the beginning stage but then increases with reaction time. When the initial concentration of iodine is lower, the amplitude is large at the beginning stage and then decreases with reaction time. An opposite influence exists for sulfuric acid. Equations for the triiodide ion reaction rate were obtained as functions of reaction time and initial concentrations at the oscillation stage. The intermediates were detected by online FTIR analysis. Based upon the experimental data in this work and in the literature, a plausible reaction mechanism was proposed for the oscillation reaction.