The present study examines the interaction of hydrogen and nitrogen plasmas with gallium in an effort to gain insights into the mechanisms behind the synergetic effect of plasma and a catalytic metal. Absorption/desorption experiments were performed, accompanied by theoretical-computational calculations. Experiments were carried out in a plasma-enhanced, Ga-packed, batch reactor and entailed monitoring the change in pressure at different temperatures. The results indicated a rapid adsorption/dissolution of the gas into the molten metal when gallium was exposed to plasma, even at a low temperature of 100 °C. The experimental observations, when hydrogen was used, indicate that gallium acts as a hydrogen sink in the presence of plasma. Similar results were obtained with Ga in the presence of nitrogen plasma. In addition, density functional theory calculations suggest a strong interaction between atomic hydrogen and molten gallium. This interaction is described as a high formation of Ga-H species on the surface, fast diffusion inside the metal, and a steady state concentration of the gas in the bulk.

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A lot of progress has been made in rechargeable lithium-ion battery (LIB) technology research in the last decade, even so, renewed developmental efforts must be pursued to better improve energy density, capacity retention and rate capability. This review discusses the role that one-dimensional (1D) nanomaterials can play towards development of next-generation LIBs. Electrode nanoengineering, interfacial kinetics and high-volume manufacturing are critical issues limiting energy density, electrochemical performance and material viability. These points are discussed, as are the advantages of deploying these nanomaterials in rechargeable LIB devices. Current data from literature is indicative of laboratory-scale success as these 1D nanomaterials display excellent capacity retention, high-rate capability and long cycle life emanating from high mechanical strength, resilience and short charge carrier diffusion distance. However, significant advances are required to translate these achievements into commercial scale deployment.

In this work, liquid phase epitaxy of gallium nitride (GaN) has been achieved using pulsed plasma nitridation of molten Ga films. Typically, continuous exposure of Ga to nitrogen plasma results in the formation of a thick GaN crust that prevents the growth of GaN layers on GaN seeds or GaN-on-sapphire substrates. The GaN crust formation on molten Ga is a consequence of a high concentration of dissolved nitrogen at the top surface of molten Ga layers. Here, we present the concept of using pulse (on/off) sequences to control the concentration of nitrogen inside the melt and enable the growth of GaN at the molten Ga−substrate interface. Results showed that the technique allows for epitaxial growth on homosubstrates and promotes the growth of additional layers on the pre-existing seeds. High-resolution transmission electron microscopy characterization confirmed epitaxial growth of GaN. A mass transport model was developed to discuss the effect of bulk recombination, diffusion, and pulsing on the concentration of nitrogen into the molten Ga. Results indicated that pulsing favored both the recombination of radicals in the bulk and the diffusion of species into the metal compared to the dissolution of radicals. As a result, the concentration of nitrogen at the surface of the metal is decreased, while the concentration of nitrogen at the molten Ga−substrate interface is increased, which allows for liquid-phase epitaxy of GaN.