Solvothermal Synthesis of Medium-Entropy Oxide Spheres for Thermocatalytic Conversion of CO to Methanol.

New chemical compositions and structures for medium- and high-entropy oxides (HEOs) currently represent a promising new avenue in materials research for a wide range of applications including catalysis, energy storage, and ceramics. To speed up further development, synthesis methods for multicationic oxides are needed for controlling features like morphology, porosity, and chemical compositions. In this work, mesoporous spinel oxide spheres with five cations are synthesized using solvothermal synthesis techniques.

Designing bifunctional perovskite catalysts for the oxygen reduction and evolution reactions.

The development of unified regenerative fuel cells (URFCs) necessitates an active and stable bifunctional oxygen electrocatalyst. The unique challenge of possessing high activity for both the oxygen reduction (ORR) and oxygen evolution (OER) reactions, while maintaining stability over a wide potential window impedes the design of bifunctional oxygen electrocatalysts. Herein, two design strategies are explored to optimize their performance.

Cobalt-free layered perovskites RBaCuFeO (R = 4f lanthanide) as electrocatalysts for the oxygen evolution reaction.

Co-based perovskite oxides are intensively studied as promising catalysts for electrochemical water splitting in an alkaline environment. However, the increasing Co demand by the battery industry is pushing the search for Co-free alternatives. Here we report a systematic study of the Co-free layered perovskite famil RBaCuFeO (R = 4f lanthanide), where we uncover the existence of clear correlations between electrochemical properties and several physicochemical descriptors.

Hydrothermal synthesis of multi-cationic high-entropy layered double hydroxides.

High-entropy materials are compositionally complex materials which often contain five or more elements. The most commonly studied materials in this field are alloys and oxides, where their composition allows for tunable materials properties. High-entropy layered double hydroxides have been recently touted as the next focus for the field of high-entropy materials to expand into.

Low Temperature Transient Liquid Phase Bonding of Alumina Ceramics with the BiO-ZnO Interlayer.

Alumina ceramics were joined by a transient liquid phase (TLP) bonding method at relatively lower temperatures, using mixed powders of BiO and ZnO with different weight ratios as interlayers between the ceramic components. Bonding was achieved at 750 °C for several of the prepared interlayer mixtures, which makes the applied approach attractive due to the relatively lower joining temperature and potentially low fabrication costs. Measurements by SEM and EDX were used to study the microstructure and chemical analysis of the obtained joints.

Aerosol-Assisted Deposition for TiO Immobilization on Photocatalytic Fibrous Filters for VOC Degradation.

Atomization and spraying are well-established methods for the production of submicrometer- and micrometer- sized powders. In addition, they could be of interest to the immobilization of photocatalytic nanoparticles onto supports because they enable the formation of microporous films with photocatalytic activity. Here, we provide a comparison of aerosol-assisted immobilization methods, such as spray-drying (SD), spray atomization (SA), and spray gun (SG), which were used for the deposition of TiO dispersions onto fibrous filter media.

Removal of MS2 and fr Bacteriophages Using MgAlO-Modified, AlO-Stabilized Porous Ceramic Granules for Drinking Water Treatment.

Point-of-use ceramic filters are one of the strategies to address problems associated with waterborne diseases to remove harmful microorganisms in water sources prior to its consumption. In this study, development of adsorption-based ceramic depth filters composed of alumina platelets was achieved using spray granulation (calcined at 800 °C). Their virus retention performance was assessed using cartridges containing granular material (4 g) with two virus surrogates: MS2 and fr bacteriophages.

Virus removal from drinking water using modified activated carbon fibers.

Activated carbon (AC) exhibits superior sorption properties compared to other porous materials, due to well-developed porous structures and high surface areas. Therefore, it is widely applied in its various forms in water purification to remove a diverse range of contaminating species. The presence of viruses in fresh water bodies poses a serious issue for human health.

Strength Analysis and Stress-Strain Deformation Behavior of 3 mol% Y-TZP and 21 wt.% AlO-3 mol% Y-TZP.

The mechanical behavior of 3 mol% YO-ZrO ceramic and 21 wt.% AlO-3 mol% YO-ZrO ceramic composite with submicron grain size was studied. Mechanical properties, such as hardness, Young's modulus, four-point bending strength, and fracture toughness of both materials were measured.

Effect of Loading and Heating History on Deformation of LaCoO.

The aim of this work was to study cyclic stress-strain deformation behavior of LaCoO as a function of loading and heating history. The ferroelastic hysteretic deformation of LaCoO at different stresses and temperatures was characterized using effective Young's modulus, hysteresis loop area and creep strain shift parameters. The deformation behavior of LaCoO was not significantly affected by the previous loading and heating history when tested at constant temperature.

Millisecond photonic sintering of iron oxide doped alumina ceramic coatings.

The sintering of alumina (AlO) traditionally occurs at high temperatures (up to ca. 1700 °C) and in significantly long times (up to several hours), which are required for the consolidation of the material by diffusion processes. Here we investigate the photonic sintering of alumina particles using millisecond flash lamp irradiation with extreme heating rates up to 10 K/min.

Ultraviolet Lithography-Based Ceramic Manufacturing (UV-LCM) of the Aluminum Nitride (AlN)-Based Photocurable Dispersions.

In this work, three-dimensional (3D) shaping of aluminum nitride (AlN) UV-curable dispersions using CeraFab 7500 device equipped with the light engine emitting 365 nm wavelength (a UV-LCM device) is presented. The purpose of this study was the shaping of AlN pieces with microchannels for the future potential use as microchannel heat exchangers. The dispersions were characterized by the means of the particle size distribution, rheological measurements, and the cure depth evaluation.

Silicon oxycarbide-antimony nanocomposites for high-performance Li-ion battery anodes.

Silicon oxycarbide (SiOC) has recently regained attention in the field of Li-ion batteries, owing to its effectiveness as a host matrix for nanoscale anode materials alloying with Li. The SiOC matrix, itself providing a high Li-ion storage capacity of 600 mA h g-1, assists in buffering volumetric changes upon lithiation and largely suppresses the formation of an unstable solid-electrolyte interface. Herein, we present the synthesis of homogeneously embedded Sb nanoparticles in a SiOC matrix with the size of 5-40 nm via the pyrolysis of a preceramic polymer.

Spark Plasma Sintered BC-Structural, Thermal, Electrical and Mechanical Properties.

The structural, thermal, electrical and mechanical properties of fully dense BC ceramics, sintered using Spark Plasma Sintering (SPS), were studied and compared to the properties of BC ceramics previously published in the literature. New results on BC's mechanical responses were obtained by nanoindentation and ring-on-ring biaxial strength testing. The findings contribute to a more complete knowledge of the properties of BC ceramics, an important material in many industrial applications.

Effects of the Layer Height and Exposure Energy on the Lateral Resolution of Zirconia Parts Printed by Lithography-Based Additive Manufacturing.

Lithography-based ceramics manufacturing (LCM) processes enable the sophisticated 3 dimensional (3D) shaping of ceramics by additive manufacturing (AM). The build-up occurs, like many other AM processes, layer by layer, and is initiated by light. The built-in digital mirror device (DMD) enables the specific exposure of desired pixels for every layer, giving as a consequence a first estimation of the printing resolution in the x and y axes.

Colloidal Transformations in MS2 Virus Particles: Driven by pH, Influenced by Natural Organic Matter.

Enteric viruses, such as enterovirus, norovirus, and rotavirus, are among the leading causes of disease outbreaks due to contaminated drinking and recreational water. Viruses are difficult to remove from water through filtration based on physical size exclusion-for example by gravity-driven filters-due to their nanoscale size. To understand virus removal in drinking water treatment systems, the colloidal nanostructure of a model virus, the MS2 bacteriophage, has been investigated in relation to the effect of pH and natural organic matter in water.

Large Planar Na-β″-AlO Solid Electrolytes for Next Generation Na-Batteries.

Large diameter (> 100 mm) planar Na-β″-AlO solid electrolytes (BASE) with thickness from 1.0 to 1.5 mm have been prepared.

Nano-Sized Copper (Oxide) on Alumina Granules for Water Filtration: Effect of Copper Oxidation State on Virus Removal Performance.

Virus removal can be successfully achieved based on an electrostatic adsorption mechanism. The key requirement for this process is to develop filter materials that can be produced by low-cost technologies and are suitable in large-scale production for real applications. In this study, we report development of spray-dried alumina granules modified with copper (oxide) nanoparticles and critically assess the effect of copper oxidation state on virus removal capacity.

Silicon Oxycarbide-Tin Nanocomposite as a High-Power-Density Anode for Li-Ion Batteries.

Tin-based materials are an emerging class of Li-ion anodes with considerable potential for use in high-energy-density Li-ion batteries. However, the long-lasting electrochemical performance of Sn remains a formidable challenge due to the large volume changes occurring upon its lithiation. The prevailing approaches toward stabilization of such electrodes involve embedding Sn in the form of nanoparticles (NPs) in an active/inactive matrix.

Functional Role of Fe-Doping in Co-Based Perovskite Oxide Catalysts for Oxygen Evolution Reaction.

Perovskite oxides have been at the forefront among catalysts for the oxygen evolution reaction (OER) in alkaline media offering a higher degree of freedom in cation arrangement. Several highly OER active Co-based perovskites have been known to show extraordinary activities and stabilities when the B-site is partially occupied by Fe. At the current stage, the role of Fe in enhancing the OER activity and stability is still unclear.

Enhanced virus filtration in hybrid membranes with MWCNT nanocomposite.

Membrane separation is proved to be a powerful tool for several applications such as wastewater treatment or the elimination of various microorganisms from drinking water. In this study, the efficiency of inorganic composite-based multi-walled carbon nanotube (MWCNT) hybrid membranes was investigated in the removal of MS2 bacteriophages from contaminated water. With this object, multi-walled carbon nanotubes were coated with copper(I) oxide, titanium(IV) oxide and iron(III) oxide nanoparticles, respectively, and their virus removal capability was tested in both batch and flow experiments.

Draw-spun, photonically annealed Ag fibers as alternative electrodes for flexible CIGS solar cells.

We explore the feasibility of Ag fiber meshes as electron transport layer for high-efficiency flexible Cu(In,Ga)Se (CIGS) solar cells. Woven meshes of Ag fibers after UV illumination and millisecond flash-lamp treatment results in a sheet resistance of 17 Ω/sq and a visible transmittance above 85%. Conductive Ag meshes are integrated into flexible CIGS cells as transparent conductive electrode (TCE) alone or together with layers of Al-doped ZnO (AZO) with various thickness of 0…900 nm.

Copper-Coated Cellulose-Based Water Filters for Virus Retention.

Despite recent efforts in modernization of water treatment facilities, the problem of access to healthy drinking water for hundreds of millions of people has still not been solved. A water filter based on Cu-coated nanofibrillated cellulose with controlled porosity was prepared by the "paper-making" method. We have optimized the proper mass and ratio of functionalized and pure nanofibrillated cellulose for the preparation of the filter.

Dynamic surface self-reconstruction is the key of highly active perovskite nano-electrocatalysts for water splitting.

The growing need to store increasing amounts of renewable energy has recently triggered substantial R&D efforts towards efficient and stable water electrolysis technologies. The oxygen evolution reaction (OER) occurring at the electrolyser anode is central to the development of a clean, reliable and emission-free hydrogen economy. The development of robust and highly active anode materials for OER is therefore a great challenge and has been the main focus of research.

Nanocrystalline TiO/SnO heterostructures for gas sensing.

The aim of this research is to study the role of nanocrystalline TiO/SnO n-n heterojunctions for hydrogen sensing. Nanopowders of pure SnO, 90 mol % SnO/10 mol % TiO, 10 mol % SnO/90 mol % TiO and pure TiO have been obtained using flame spray synthesis (FSS). The samples have been characterized by BET, XRD, SEM, HR-TEM, Mössbauer effect and impedance spectroscopy.