4 research outputs found

    Passivated Iodine Pentoxide Oxidizer for Potential Biocidal Nanoenergetic Applications

    No full text
    Iodine pentoxide (I<sub>2</sub>O<sub>5</sub>), also known as diiodine pentoxide, is a strong oxidizer which has been recently proposed as an iodine-rich oxidizer in nanoenergetic formulations, whose combustion products lead to molecular iodine as a biocidal agent. However, its highly hygroscopic nature hinders its performance as a strong oxidizer and an iodine releasing agent and prevents its implementation. In this work, we developed a gas phase assisted aerosol spray pyrolysis which enables creation of iron oxide passivated I<sub>2</sub>O<sub>5</sub>. Transmission electron microscopy elemental imaging as well as temperature-jump mass spectrometry confirmed the core shell nature of the material and the fact that I<sub>2</sub>O<sub>5</sub> could be encapsulated in pure unhydrated form. Combustion performance finds an optimal coating thickness that enables combustion performance similar to a high performing CuO based thermite

    Surface Charge Density Determination of Single Conical Nanopores Based on Normalized Ion Current Rectification

    No full text
    Current rectification is well known in ion transport through nanoscale pores and channel devices. The measured current is affected by both the geometry and fixed interfacial charges of the nanodevices. In this article, an interesting trend is observed in steady-state current–potential measurements using single conical nanopores. A threshold low-conductivity state is observed upon the dilution of electrolyte concentration. Correspondingly, the normalized current at positive bias potentials drastically increases and contributes to different degrees of rectification. This novel trend at opposite bias polarities is employed to differentiate the ion flux affected by the fixed charges at the substrate–solution interface (surface effect), with respect to the constant asymmetric geometry (volume effect). The surface charge density (SCD) of individual nanopores, an important physical parameter that is challenging to measure experimentally and is known to vary from one nanopore to another, is directly quantified by solving Poisson and Nernst–Planck equations in the simulation of the experimental results. The flux distribution inside the nanopore and the SCD of individual nanopores are reported. The respective diffusion and migration translocations are found to vary at different positions inside the nanopore. This knowledge is believed to be important for resistive pulse sensing applications because the detection signal is determined by the perturbation of the ion current by the analytes

    Facile one-step synthesis and enhanced photocatalytic activity of WC/ferroelectric nanocomposite

    No full text
    The development of noble-metal-free co-catalysts is seen as a viable strategy for improving the performance of semiconductor photocatalysts. Although the photocatalytic efficiency of ferroelectrics is typically low, it can be enhanced through incorporation of co-catalyst into nanocomposites. Here, we demonstrate the influence of ferroelectricity on the decolorization of Rhodamine B under simulated solar light using RbBi2Ti2NbO10 and compared the performance with nonferroelectric RbBi2Nb5O16. The decolorization rate for RbBi2Ti2NbO10 was 5 times greater than RbBi2Nb5O16. This behaviour can be explained in terms of ferroelectric polarization, which drives separation of the charge carriers. The photocatalytic activity of the RbBi2Ti2NbO10 was further enhanced to over 30 times upon preparing nanocomposite with tungsten carbide (WC) through high energy ball milling. This enhancement was not only attributed to the increased specific surface area, but also to the incorporated WC co-catalyst which also serves as source of plasmonic hot electrons and extends the photocatalytic activity into the visible light range. The WC/RbBi2Ti2NbO10 nanocomposite shows interesting water oxidation property and evolves O2 with a rate of 68.5 µmol h-1 g -1 and the quantum yield of 3% at 420 nm. This work demonstrates a simple route for preparing WC containing nano ferroelectric composites for solar energy conversion applications
    corecore