No abstract

No abstract

Density functional theory simulations were performed to investigate the structural, electronic, and electrochemical properties of the two-dimensional α-SiX (X = N, P) monolayers as anode material in Li-ion batteries (LIBs). Our result indicates that α-SiX monolayers have excellent mechanical, dynamical, and thermal stability. The obtained adsorption energy values suggest that the Li atom adsorption over α-SiX is a favorable process. According to the Löwdin charge transfer and partial density of states analysis, charge transfer takes place from Li atom to α-SiX monolayers. From the band structure plots, we observed that after the adsorption of a single Li atom, the α-SiX monolayers are converted into a metallic state from the semiconductor state and remain in the metallic state for the different adsorption concentrations of Li atoms, which is essential to facilitate the diffusion of stored electrons. The calculated specific storage capacity is 956.16 and 733.66 mA h g–1 for α-SiN and α-SiP monolayers, respectively, which is remarkably higher than that of the conventional anode materials (such as graphite and TiO2). Ab initio molecular dynamics simulations confirm the room-temperature stability of the α-SiX monolayers at the maximum loading of Li atoms. The lower diffusion energy barriers of 0.30 eV (for α-SiN monolayers) and 0.16 eV (for α-SiP monolayers) ensure good diffusivity of ions over monolayers. The calculated open-circuit voltage is also favorable for battery applications. The aforementioned findings suggest that the α-SiX monolayers could be beneficial and compelling host anode material for high-performance LIBs.

The development of copper nanoparticles (CuNPs) with antimicrobial activities shows high potential for various clinical applications. We herein synthesized Poloxamer(P407)-assisted CuNPs with improved oxidative stability using a simple process that included environment friendly Vitamin C (ascorbic acid) as a reducing agent and nontoxic P407 polymer as a stabilizing agent. To optimize the reducing agent, the effect of the molar ratio of ascorbic acid-to-Cu 2 + salt was investigated through fluorescence measurements. The UV-Visible spectrum presented that the inclusion of P407 improved the efficiency of CuNPs synthesis. In addition, DLS demonstrated that when the concentration of P407 was increased, the particle size of CuNPs was reduced. According to the XRD patterns, all the CuNPs are fcc-structured and crystalline. The FE-SEM and EDX images indicated the cubic morphology and the absence of any oxides of copper. The synthesized CuNPs have different particle sizes, showing strong antimicrobial activities against Gram-negative and Gram-positive bacteria as well as funguses. Our findings suggest that P407-assisted CuNPs could be a new way to fight both human and plant pathogens.

No abstract