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Magnesium hydride (MgH2) is a promising material for hydrogen storage because of its abundance and beneficial properties, such as high storage capacity and cost-effectiveness under mild conditions. Despite of these benefits, MgH2 unfavorable thermodynamics and kinetics make it difficult to use in real applications. In this work, the hydrogen storage properties of MgH2have been improved using Al-Cu-Fe-Ni-Cr high entropy alloy (HEA) based catalysts, which has been synthesized via mechanical alloying. The experimental findings show that the beginning desorption temperature of MgH2significantly lowered from 425{\deg}C to 180{\deg}C by adding 5 wt. % Al-Cu-Fe-Ni-Cr HEA in MgH2. Moreover, the catalyst shows enhanced kinetics, attaining 7.3 wt. % hydrogen absorption in 3 minutes at 320{\deg}C with 15 atm hydrogen pressure, and ~5 wt. % desorption in 6 minutes at 320{\deg}C. These results highlight, how much lower its desorption temperature is than those of other well-known catalysts. Over a span of 25 cycles, MgH2 catalyzed by Al-Cu-Fe-Ni-Cr HEA exhibits remarkable cyclic stability with negligible fluctuations (~ 0.05 wt. %).After a thorough characterization of the materials, a workable catalytic mechanism for HEA was proposed in light of the results., Comment: 39 pages, 10 Figures

Per- and polyfluoroalkyl substances (PFAS), often referred as "forever chemicals," are pervasive environmental pollutants due to their resistance to degradation. Among these, perfluorooctanoic acid (PFOA) poses significant threats to human health, contaminating water sources globally. Here, we have demonstrated the potential of a novel electrochemical sensor based on two-dimensional (2D) aluminium-based multicomponent quasicrystals (2D-Al QC) for the ultrasensitive sub-picomolar level detection of PFOA. The 2D-Al QC-inked electrode was employed here to detect PFOA by differential pulse voltammetry (DPV). The limit of detection (LoD) achieved is 0.59 +/- 0.05 pM. The sensor was evaluated for selectivity with other interfering compounds, repeatability of cycles, and reproducibility for five similar electrodes with a deviation of 0.8 %. The stability of the sensor has also been analysed after ninety days ,which shows a minimal variation of 15%. Spectroscopic techniques and theoretical calculations were further utilized to understand the interaction between the 2D-Al QC and PFOA. The results demonstrate that the 2D-Al QC offers a promising platform for the rapid and sensitive detection of PFOA, potentially addressing current environmental monitoring challenges.

In the present investigation, the chemical leaching of the poly-grain Al65Cu15Co20 and Al65Cu20Co15 decagonal quasicrystalline alloy have been studied. The polished surfaces of as-cast alloys were leached with 10 mole NaOH solution for 0.5- 8 hours. The x-ray diffraction, scanning electron microscopy and transmission electron microscopy techniques have been used for structural and microstructural characterization. Energy dispersive x-ray analysis has been carried out for chemical composition analysis. Chemical leaching exclusively removes the Al from the surfaces of the Al65Cu15Co20 and Al65Cu20Co15 decagonal quasicrystalline alloys, consequently by the formation of porous structure containing nano size particles of Cu, Co and their oxides have been observed. Al65Cu15Co20 exhibits high porosity in comparison to Al65Cu20Co15 alloy, however the size of the precipitated nano-particles i.e. Cu, Co, Cu2O and CuO were smaller in the case of Al65Cu20Co15 alloy. The energy dispersive X-ray analysis mapping suggests homogeneous distribution of Cu and Co found on the leached surface and the presence of oxygen was also detected., Comment: 14 pages, 10 figures

Recent theoretical and practical research has focused on multi-component High Entropy Alloys (HEAs), which have superior mechanical and functional properties than standard alloys based on a single major element, thereby establishing a new field. A multi-component HEA contains five or more primary elements at concentrations ranging from 5 to 35 atomic percent. We examined the microstructure and mechanical properties of TiVCoNiMn2 HEA. The mixing enthalpy and other thermodynamic parameters were determined using Meidma's model. TiVCoNiMn2 exhibits a mixing enthalpy of -15.6 kJ/mol and an atomic radius mismatch of approximately 10.03%. HEA is derived from both hydride and non-hydride-producing elements. This could be a useful hydrogen storage material. The hydrogen absorption/desorption capabilities of these HEAs are promising., Comment: 5 pages, 4 Figures

Thin film quasicrystal coatings have unique properties such as very high electrical and thermal resistivity and very low surface energy. A nano quasicrystalline thin film of icosahedral Al-Ga-Pd-Mn alloy, has produced by flash evaporation followed by annealing. Attempts will be made to discuss the micromechanisms for the formation of quasicrystalline thin film in Al-Ga-Pd-Mn alloys, Comment: 13 pages, 5 Figures. arXiv admin note: substantial text overlap with arXiv:0806.2382