Effect of coupling crater structure and Ag nanoparticles on SERS enhancement

Journal of Materials Science - This study was aimed at enhancing surface plasmon resonance through a combination of Ag nanoparticles (NPs) and an asymmetric crater structure capable of...     

Anion conductive tetra-sulfonium hydroxides poly(fluorenylene ether sulfone) membrane for fuel cell application

A series of anion exchange membranes of poly (fluorenylene ether sulfone) containing tertiary sulfonium hydroxide-functionalized fluorenyl groups were synthesized by sequential polycondensation, chloromethylation, substitution with dimethyl sulfide and ion exchange. They showed excellent solubility in polar aprotic solvents. Consequently, flexible and tough alkaline membranes with varying ionic contents were obtained by an anion exchange of tertiary sulfonium chloride polymers with 1.0 M KOH at room temperature. Different levels of substitution were performed to achieve high ionic conductivity as well as upholding the membranes’ mechanical stability. The tertiary sulfonium membranes demonstrated lower water uptake compared to quaternary ammonium membrane. High hydroxide ion conductivity was achieved up to 18.3 mS cm^?1 at 80 °C with the membrane of the highest ion exchange capacity (IEC, 1.51 mmol g^?1). The resulting alkaline polymers were characterized by ¹H NMR, FT-IR, thermogravimetric analysis (TGA), water uptake, IEC, atomic force microscopic (AFM) images.     

Investigation of discharge reaction mechanism of lithium|liquid electrolyte|sulfur battery

The influence of current density on the discharge reaction of Li–S batteries is investigated by discharge tests (first discharge curve), differential scanning calorimetry (DSC), X-ray diffraction (XRD) (discharge products), and scanning electron microscopy (the surface morphology of sulfur electrodes). The first discharge capacity and the plateau potential both decrease with increasing current density. When the current density is increased from 100 to 1600 mA g⁻¹ S, the discharge capacity decreases from 1178 to 217 mAh g⁻¹ S.     

The discharge properties of Na/Ni3S2 cell at ambient temperature

The discharge properties of a Na/Ni₃S₂ cell using 1 M NaCF₃SO₃ in tetra(ethylene glycol)dimethyl ether liquid electrolyte were investigated at room temperature. The products were characterized by X-ray diffraction, scanning electron microscopy and energy dispersive spectroscopy. Electrochemical properties of Na/Ni₃S₂ cells were also presented by cyclic voltammetry and the galvanostatic current method. Na/Ni₃S₂ cells have an initial discharge capacity of 420 mAh g⁻¹ with a plateau potential at 0.94 V versus Na/Na⁺. After the first discharge, Ni₃S₂ and Na react at room temperature and then form sodium sulfide (Na₂S) and nickel. Sodium ion can be partially deintercalated from Na₂S charge reaction. The discharge process can be explained as follows: Ni₃S₂ + 4Na ↔ 3Ni + 2Na₂S.