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Structural, optical, and morphological stability of ZnO nano rods under shock wave loading conditions
摘要： Shock wave recovery experiment on crystalline materials is a hot research topic for aerospace applications. In this research article, authors present and demonstrate the stability of physical properties of ZnO nano rods (ZnO NRs) under shock wave loaded conditions. The test sample is synthesized by hydrothermal method and the shock waves were generated using a table top semi automatic pressure driven shock tube. A shock wave of 2.2 Mach number which has a transient pressure of 2.0 MPa and temperature 864 K was made to strike four test samples for the counts of 50,100,150 and 200, respectively. The shock loaded samples were subjected to XRD and optical analysis so as to understand the influence of shock waves in the structural and optical properties. The results show that ZnO NRs have magnificent molecular, optical, structural and morphological stability for 50,100 and 150 shocks. Though, when the number of shock pulses was increased to 200 and a blue shift was observed in UV-Vis spectrum, no changes in structural properties took place which was evidenced from XRD. From this shock wave recovery experiment, it is clear that ZnO NRs are highly stable against shock waves and hence this material is suggested for the aerospace and military applications.
关键词： ZnO nano rods,Aerospace applications,Structure stability,Shock waves
更新于2025-09-23 15:23:52
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Polyaniline supported g-C3N4 quantum dots surpass benchmark Pt/C: Development of morphologically engineered g-C3N4 catalysts towards a??metal-freea?? methanol electro-oxidation
摘要： In spite of being one of the most promising energy conversion devices, the state of the art in the efficient application of direct methanol fuel cell is far from being optimal mostly because of its heavy reliance on expensive Pt anode that suffers from easy CO poisoning. Here, in this work for the first time in literature, we have explored the catalytic efficacy and improved mass activity of morphologically engineered metal-free graphitic carbon nitride towards methanol oxidation. The 2D nano-sheets, 1D nano-rods, and 0D quantum dots of graphitic carbon nitride are successfully prepared from bulk by a thermo-chemical etching process. The materials are thoroughly characterized with the help of X-ray diffraction, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, field emission scanning electron microscopy, transmission electron microscopy, luminescence study and are studied for methanol oxidation reaction in basic condition with the help of cyclic voltammetry. Among the three different dimensional g-C3N4 materials, the quantum dots show higher methanol oxidation activity due to its abundant edges in nano morphology and maximum atomic percentages of active site of pyridinic N. The 0D g-C3N4 when supported on conducting polyaniline, not only shows higher electrocatalytic methanol oxidation activity than the commercial Pt/C but also demonstrates excellent CO tolerance to be a suitable and applicable metal-free anode catalyst in direct methanol fuel cell applications. The electrostatic interaction between 0D g-C3N4 and conducting polyaniline (PANI) fibres may have improved the electrical conductivity and methanol adsorption of CNQD-PANI electrocatalyst and also played a role in oxidizing the adsorbed CO to upsurge the CO tolerance.
关键词： Nano-rods,Metal-free electrocatalysis,Methanol oxidation reaction,Quantum dots,g-C3N4,Nano-sheets
更新于2025-09-19 17:13:59