EFFECT OF Al₂O₃-RO RATIO ON THE STRUCTURE AND PROPERTIES OF ALKALINE EARTH ALUMINOSILICATE GLASS BASED ON THE MOLECULAR DYNAMICS SIMULATION

The molecular dynamics (MD) simulation method was used to study the influence of the Al₂O₃-RO (R=Ca, Mg) ratio on the structure and properties of CaO-MgO-Al₂O₃-SiO₂-Na₂O glass at high temperatures. The micro-structure characteristics, degree of network polymerisation (DNP), and high-temperature viscosity of the glass melts were analysed. The results showed that the coordination number of Si4+ and Al3+ remained about 4 in the process of replacing Al₂O₃ with RO. The silicon-oxygen and aluminium-oxygen tetrahedron content showed a decreasing trend with a decrease in the Al₂O₃ content, the bridging oxygen content decreased, and the degree of the network polymerisation of the glass decreased from 3.33 to 2.79. The decrease in the Al₂O₃ content also caused a rapid decrease in the glass fibre-forming temperature from 1637.66K to 1552.87K. According to the molecular dynamics calculation, the linear relationship between the DNP and fibre-forming temperature was obtained

EFFECT OF THE CaO-MgO-Al₂O₃-SiO₂ GLASS COMPOSITION ON THE MICROSTRUCTURE AND RHEOLOGICAL PROPERTIES FROM A MOLECULAR DYNAMICS SIMULATION

By adjusting the ratio of SiO₂ /RO (R=Ca, Mg), this article studied the atomic structure of CaO-MgO-Al₂O₃-SiO₂ glassy melts by a molecular dynamics simulation. The Pair distribution function (PDF), Coordination number (CN), bridging oxygen (BO), non-bridging oxygen (NBO), and Qn were utilised to characterise the glass structure. The results indicated that the content of the bridging oxygen was decreased with the RO replacing the SiO2. The total content of Q⁴ in the tetrahedron changed significantly from 34.11% to 18.06%. Meanwhile, the NBO/T parameter increased from 1.298 to 1.555. In the corresponding viscosity test, the melting temperature, fitted by the MYEGA equation, also decreased with the decrease in the SiO₂ content, and the fragility value increased from 39.12 to 53.20. Finally, the fragility and NBO/T were linked to describing the relationship between the mid-range structure and the rheological property. Moreover, the analyses showed that they had a linear relationship

Cobalt Molybdenum Oxide Derived High-Performance Electrocatalyst for the Hydrogen Evolution Reaction

The design and synthesis of high-performance hydrogen evolution reaction (HER) catalysts requires an overall consideration of intrinsic activity and number of active sites as well as electric conductivity. We herein report a facile synthesis of a cost-effective catalyst that can simultaneously address these key issues. A cobalt molybdenum oxide hydrate (CoMoO₄·<i>n</i>H₂O) with a 3D hierarchical nanostructure can be readily grown on nickel foam using a hydrothermal method. Calcination treatment of this precursor material under a reductive atmosphere resulted in the formation of Co nanoparticles on the Co₂Mo₃O₈ surface, which worked in concert to act as active sites for the HER. In addition, the resulting Co₂Mo₃O₈ from the dehydration and reduction reactions of CoMoO₄·<i>n</i>H₂O showed remarkable increases in both active surface area and electrical conductivity. As a consequence of these favorable attributes, the catalyst exhibited electrocatalytic performance comparable to that of the commercial Pt/C catalyst for the HER in alkaline solution, which is promising for practical water-splitting applications