Key developments in magnesiothermic reduction of silica: insights into reactivity and future prospects.

Porous Si (p-Si) nanomaterials are an exciting class of inexpensive and abundant materials within the field of energy storage. Specifically, p-Si has been explored in battery anodes to improve charge storage capacity, to generate clean fuels through photocatalysis and photoelectrochemical processes, for the stoichiometric conversion of CO to value added chemicals, and as a chemical H storage material. p-Si can be made from synthetic, natural, and waste SiO sources through a facile and inexpensive method called magnesiothermic reduction (MgTR).

Overcoming copper-induced conversion reactions in nickel disulphide anodes for sodium-ion batteries.

Employing copper (Cu) as an anode current collector for metal sulphides is perceived as a general strategy to achieve stable cycle performance in sodium-ion batteries, despite the compatibility of the aluminium current collector with sodium at low voltages. The capacity retention is attributed to the formation of copper sulphide with the slow corrosion of the current collector during cycling which is not ideal. Conventional reports on metal sulphides demonstrate excellent electrochemical performances using excessive carbon coatings/additives, reducing the overall energy density of the cells and making it difficult to understand the underlying side reaction with Cu.

Impact of an Underlying 2DEG on the Performance of a p-Channel MOSFET in GaN.

The influence of an underlying 2-dimensional electron gas (2DEG) on the performance of a normally off p-type metal oxide semiconductor field effect transistor (MOSFET) based on GaN/AlGaN/GaN double heterojunction is analyzed via simulations. By reducing the concentration of the 2DEG, a greater potential can be dropped across the GaN channel, resulting in enhanced electrostatic control. Therefore, to minimize the deleterious impact on the on-state performance, a composite graded back-to-back AlGaN barrier that enables a trade-off between n-channel devices and Enhancement-mode (E-mode) p-channel is investigated.

Exploiting nanoscale effects enables ultra-low temperature to produce porous silicon.

The magnesiothermic reduction (MgTR) of silica has been recently shown to produce porous silicon which can be used in applications such as photocatalysis and energy storage. MgTR typically requires ≥650 °C to achieve meaningful conversions. However, high temperatures are detrimental to the highly desired porosity of silicon, while also raising doubts over the sustainability of the process.

A high throughput computational investigation of the solid solution mechanisms of actinides and lanthanides in zirconolite.

In this work, we perform a theoretical investigation of the actinide and lanthanide solid solution mechanisms of zirconolite-2M, prototypically CaZrTiO, as a candidate immobilisation matrix for plutonium. Solid solution energies were calculated using static atomistic simulations by means of the General Utility Lattice Program, for formulations of relevance to ceramic wasteform deployment, with substitution on the Ca and Zr sites by Ce, Pu, Th, and U, and appropriate charge balance by substitution of Al or Fe on Ti sites. In simple solid solutions involving substitution on the Zr site, we found that whereas substitution of Ce, U and Pu were energetically favoured, substitution of Th was not energetically favoured.

Understanding Surface Modifications Induced via Argon Plasma Treatment through Secondary Electron Hyperspectral Imaging.

Understanding the effects that sterilization methods have on the surface of a biomaterial is a prerequisite for clinical deployment. Sterilization causes alterations in a material's surface chemistry and surface structures that can result in significant changes to its cellular response. Here we compare surfaces resulting from the application of the industry standard autoclave sterilisation to that of surfaces resulting from the use of low-pressure Argon glow discharge within a novel gas permeable packaging method in order to explore a potential new biomaterial sterilisation method.

Enabling scale-up of mesoporous silicon for lithium-ion batteries: a systematic study of a thermal moderator.

The volume expansion of silicon during cycling of a lithium-ion battery (LIB) leads to degradation and capacity loss. Porous silicon can address many of the issues faced by silicon active materials and has previously been shown to have excellent cyclability. Recently we have uncovered the mechanisms underpinning the pore evolution in magnesiothermic reduction (MgTR) of silica and further demonstrated that it has the potential to produce porous silicon in a scalable and economic manner [, 2020, , 4938].

Degradation of Anthraquinone Dyes from Effluents: A Review Focusing on Enzymatic Dye Degradation with Industrial Potential.

Up to 84 000 tons of dye can be lost in water, and 90 million tons of water are attributed annually to dye production and their application, mainly in the textile and leather industry, making the dyestuff industry responsible for up to 20% of the industrial water pollution. The majority of dyes industrially used today are aromatic compounds with complex, reinforced structures, with anthraquinone dyes being the second largest produced in terms of volume. Despite the progress on decolorization and degradation of azo dyes, very little attention has been given to anthraquinone dyes.

Light-driven locomotion of a centimeter-sized object at the air-water interface: effect of fluid resistance.

A centimeter-sized flat-headed push pin with photothermal properties can be moved on a water surface by a simple near-infrared laser. Using light as an external stimulus allows for the remote control of the timing, direction and velocity of its locomotion. It has been clarified that the vertical orientation of the pin at the air-water interface affects the friction of locomotion, and therefore velocity and acceleration.

β-GaO nanorod arrays with high light-to-electron conversion for solar-blind deep ultraviolet photodetection.

Vertically aligned nanorod arrays (NRAs), with effective optical coupling with the incident light and rapid electron transport for photogenerated carriers, have attracted much interest for photoelectric devices. Herein, the monoclinic β-GaO NRAs with an average diameter/length of 500 nm/1.287 μm were prepared by the hydrothermal and post-annealing method.

Chemistry of black leaf films synthesised using rail steels and their influence on the low friction mechanism.

Fallen leaves are the main issues for train operations in the autumn season due to their low friction coefficient (COF), leading to signals being passed dangerously and amended timetables. The main aim of this study was to elucidate the mechanism of low friction due to black leaf films, which are often seen on leaf-contaminated rails. A black material was successfully synthesised in the laboratory with water extracts from sycamore leaves and a plate of R260 rail steel.

SPH modelling of depth-limited turbulent open channel flows over rough boundaries.

A numerical model based on the smoothed particle hydrodynamics method is developed to simulate depth-limited turbulent open channel flows over hydraulically rough beds. The 2D Lagrangian form of the Navier-Stokes equations is solved, in which a drag-based formulation is used based on an effective roughness zone near the bed to account for the roughness effect of bed spheres and an improved sub-particle-scale model is applied to account for the effect of turbulence. The sub-particle-scale model is constructed based on the mixing-length assumption rather than the standard Smagorinsky approach to compute the eddy-viscosity.

A theoretical study of dispersion-to-aggregation of nanoparticles in adsorbing polymers using molecular dynamics simulations.

The properties of polymer-nanoparticle (NP) mixtures significantly depend on the dispersion of the NPs. Using molecular dynamics simulations, we demonstrate that, in the presence of polymer-NP attraction, the dispersion of NPs in semidilute and concentrated polymers can be stabilized by increasing the polymer concentration. A lower polymer concentration facilitates the aggregation of NPs bridged by polymer chains, as well as a further increase of the polymer-NP attraction.