RESUMEN
Li-B alloys present higher voltages and better power performances than those of conventional Li-Al and Li-Si anodes for thermal batteries. Herein, the electrochemical characteristics of the Li-B alloy in the LiCl-LiBr-KBr electrolyte, including the discharge mechanism, charge transfer coefficient and exchange current density, were investigated in the temperature range of 623-823 K by open circuit potential (OCP), cyclic voltammetry (CV), chronopotentiometry (CP), linear sweep voltammetry (LSV) and electrochemical impedance spectroscopy (EIS) techniques. Consequently, the OCP of the Li-B alloy in the LiCl-LiBr-KBr electrolyte is close to that of pure lithium at the investigated temperatures. The discharge of the Li-B alloy electrode includes electrochemical dissolution of free lithium (Li â Li+) and compounded lithium (LiB â Li+ + B). The charge transfer coefficient in the anodic direction (Li â Li+) is about 0.63 at 623 K, which slightly increases as the temperature increases. The exchange current density of the Li (Li-B)/Li+ couple determined by the EIS method increases from 3.84 A cm-2 to 8.40 A cm-2 when the temperature increases from 623 to 823 K, corresponding to an activation energy of 16.4 kJ mol-1. These results suggest that the Li-B anode allows ultrahigh-rate discharge in thermal batteries.
RESUMEN
In this work, a simple, selective, and sensitive probe for hemoglobin based on the quenched fluorescence of silicon nanoparticles (SiNPs) was fabricated. The SiNPs were synthesized by a simple hydrothermal treatment from N-[3-(trimethoxysilyl)propyl]ethylenediamine and sodium citrate. The as-prepared SiNPs exhibited good water-solubility and high fluorescence with the quantum yield of 70%. The fluorescence of the SiNPs could be remarkably quenched by hemoglobin. A wide linear range was obtained from 50 nM to 4000 nM with a LOD of 40 nM. The quenching mechanism was investigated by UV-Vis absorption spectrometry and time-resolved fluorescence spectrometry.
Asunto(s)
Colorantes Fluorescentes , Hemoglobinas/análisis , Nanopartículas/química , Silicio/química , Espectrometría de Fluorescencia/métodos , Colorantes Fluorescentes/síntesis química , Colorantes Fluorescentes/química , Límite de Detección , Modelos Lineales , Cloruro de Sodio/química , SolubilidadRESUMEN
Fluorescent silicon nanoparticles have attracted much attention in recent years due to their superior optical properties, strong photostability, low toxicity, and favorable biocompatibility. In this paper, we have prepared imidazolium ionic liquid-functionalized silicon nanoparticles (IL@SiNPs) via a simple one-pot hydrothermal route from 1-(trimethoxysilyl)propyl-3-methylimidazolium chloride that was denoted as [SmIm]Cl and sodium citrate. The synthetic IL@SiNPs could be a novel label-free sensing probe for sensitive and selective detection of Hg2+ ions with energy transfer from IL@SiNPs to Hg2+. A good linear relationship was obtained from 0 to 40 µmol L-1 with a detection limit of 0.45 µM. Furthermore, the solubility of the IL@SiNPs can be facilely converted by anion exchange without complex chemical modification. The ionic liquid-modified SiNPs may show great promise in biological and environmental applications due to their excellent biocompatibility and optical performance.