CQDs-Doped Magnetic Electrospun Nanofibers: Fluorescence Self-Display and Adsorption Removal of Mercury(II)

This paper reports the carbon quantum dots-doped magnetic electrospinning nanofibers for the self-display and removal of Hg­(II) ions from water. The fluorescent carbon quantum dots and magnetic Fe₃O₄ nanoparticles were pre-prepared successfully, and they appeared to be homogeneously dispersed in nanofibers via electrospinning. During the sorption of Hg­(II) ions, the significant fluorescence signals of nanofibers gradually declined and exhibited a good linear relationship with cumulative adsorption capacity, which could be easily recorded by the photoluminescence spectra. The sorption performance of mercury ions onto the nanofibers was investigated in terms of different experimental factors including contact time, solution pH value, and initial ion concentration. Considering the actual parameters, the nanofibers were sensitive self-display adsorption system for Hg­(II) ions in the existence of other cation. The sorption data were described by different kinetic models, which indicate that the whole sorption was controlled by chemical adsorption. The intraparticle diffusion mass transfer was not obvious in this system, which further proved the uniform adsorption and even fluorescence quenching in nanofibers. Additionally, the nanocomposite fiber could regenerate in several cycles with no significant loss of adsorption capacity and fluorescence intensity. Thus, the nanofibers are promising alternatives for environmental pollution incidents. It is especially competent due to its high efficiency for self-display and removal of high concentration of mercury ions

Cellulosic Biomass-Reinforced Polyvinylidene Fluoride Separators with Enhanced Dielectric Properties and Thermal Tolerance

Safety issues are critical barriers to large-scale energy storage applications of lithium-ion batteries (LIBs). Using an ameliorated, thermally stable, shutdown separator is an effective method to overcome the safety issues. Herein, we demonstrate a novel, cellulosic biomass-material-blended polyvinylidene fluoride separator that was prepared using a simple nonsolvent-induced phase separation technique. This process formed a microporous composite separator with reduced crystallinity, uniform pore size distribution, superior thermal tolerance, and enhanced electrolyte wettability and dielectric and mechanical properties. In addition, the separator has a superior capacity retention and a better rate capability compared to the commercialized microporous polypropylene membrane. This fascinating membrane was fabricated via a relatively eco-friendly and cost-effective method and is an alternative, promising separator for high-power LIBs