Evaluation of Mechanochemically Prepared CePO∙HO Nanoparticles as UV Filter for Photoprotective Formulations.

Rhabdophane, CePO∙HO, nanoparticles were prepared by mechanochemical synthesis with different durations and thoroughly characterized by various characterization techniques. X-ray diffraction analysis showed that the optimal synthesis duration was 15 min, since, in this case, pure rhabdophane is obtained, without traces of contamination by the vessel material. The size of the obtained nanoparticles, as determined from high-resolution transmission electron microscopy images, was around 5 nm.

Structure-Stability Relationships in Pt-Alloy Nanoparticles Using Identical-Location Four-Dimensional Scanning Transmission Electron Microscopy and Unsupervised Machine Learning.

Nanoparticulate electrocatalysts for the oxygen reduction reaction are structurally diverse materials. Scanning transmission electron microscopy (STEM) has long been the go-to tool to obtain high-quality information about their nanoscale structure. More recently, its four-dimensional modality has emerged as a tool for a comprehensive crystal structure analysis using large data sets of diffraction patterns.

Beeswax-poly(vinyl alcohol) composite films for bread packaging.

The study aimed to improve the barrier characteristics of polyvinyl alcohol (PVA) film by adding beeswax (BW) and glycerin and by heat treatment in order to become a potential suitable material for bread packaging. XRD, FTIR and XPS showed new cross-links between PVA and beeswax demonstrating the composite nature of the film. TGA-DTA showed that glycerin reduced the dehydration and that the beeswax improved theirs thermal stability.

Impact of stress-induced precipitate variant selection on anisotropic electrical properties of piezoceramics.

Precipitation hardening has been recently validated as a new mechanism for domain wall pinning and mechanical loss reduction in piezoelectrics. While anisometric precipitates have high pinning strengths, there is limited knowledge about the electrical anisotropy of the precipitation-hardened piezoceramics. In the present work, we successfully orient the precipitates in LiNaNbO piezoceramics by applying a uniaxial stress during the aging and studied its electrical anisotropy.

Supramolecular Solid Complexes between Bis-pyridinium-4-oxime and Distinctive Cyanoiron Platforms.

The structural features and optical properties of supramolecular cyanoiron salts containing bis-pyridinium-4-oxime Toxogonin (TOXO) as an electron acceptor are presented. The properties of the new TOXO-based cyanoiron materials were probed by employing two cyanoiron platforms: hexacyanoferrate(II), [Fe(CN)] (HCF); and nitroprusside, [Fe(CN)(NO)] (NP). Two water-insoluble inter-ionic donor-acceptor phases were characterized: the as-prepared microcrystalline reddish-brown (TOXO)[Fe(CN)]·8HO () with a medium-responsive, hydrochromic character; and the dark violet crystalline (TOXO)[Fe(CN)]·3.

Transient Ruddlesden-Popper-Type Defects and Their Influence on Grain Growth and Properties of Lithium Lanthanum Titanate Solid Electrolyte.

Lithium lanthanum titanate (LLTO) perovskite is one of the most promising electrolytes for all-solid-state batteries, but its performance is limited by the presence of grain boundaries (GBs). The fraction of GBs can be significantly reduced by the preparation of coarse-grained LLTO ceramics. In this work, we describe an alternative approach to the fabrication of ceramics with large LLTO grains based on self-seeded grain growth.

The Kondo Effect in CeLaLuScY ( = 0.05-1.0) High-Entropy Alloys.

In the search for electronic phenomena in high-entropy alloys (HEAs) that go beyond the independent-electron description, we have synthesized a series of hexagonal rare earth (RE)-based HEAs: CeLaLuScY ( = 0.05-1.0).

Mnemonic Rutile-Rutile Interfaces Triggering Spontaneous Dissociation of Water.

Water interaction with mineral surfaces is a complex living system decisive for any photocatalytic process. Resolving the atomistic structure of mineral-water interfaces is thus crucial for understanding these processes. Fibrous rutile TiO , grown hydrothermally on twinned rutile seeds under acidic conditions, is studied in terms of interface translation, atomic structure, and surface chemistry in the presence of water, by means of advanced microscopy and spectroscopy methods combined with structure modeling and density functional theory calculations.

Microwave-Assisted Synthesis of Pt/SnO for the Catalytic Reduction of 4-Nitrophenol to 4-Aminophenol.

In this study, we present a new approach for the synthesis of Pt/SnO catalysts using microwave radiation. Pt(IV) and Sn(IV) inorganic precursors (HPtCl and SnCl) and ammonia were used, which allowed the controlled formation of platinum particles on the anisotropic SnO support. The synthesized Pt/SnO samples are mesoporous and exhibit a reversible physisorption isotherm of type IV.

Cation Adsorption in TiO Nanotubes: Implication for Water Decontamination.

TiO nanotubes constitute very promising nanomaterials for water decontamination by the removal of cations. We combined a range of experimental techniques from structural analyses to measurements of the properties of aqueous suspensions of nanotubes, with (i) continuous solvent modeling and (ii) quantum DFT-based simulations to assess the adsorption of Cs on TiO nanotubes and to predict the separation of metal ions. The methodology is set to be operable under realistic conditions, which, in this case, include the presence of CO that needs to be treated as a substantial contaminant, both in experiments and in models.

"" Advanced Characterization Platform for Studying Electrocatalytic Iridium Nanoparticles Dispersed on TiON Supports Prepared on Ti Transmission Electron Microscopy Grids.

Aiming at speeding up the discovery and understanding of promising electrocatalysts, a novel experimental platform, , the , is introduced. It is based on state-of-the-art physicochemical characterization and atomic-scale tracking of individual synthesis steps as well as subsequent electrochemical treatments targeting nanostructured composites. This is provided by having the entire experimental setup on a transmission electron microscopy (TEM) grid.

Winning Combination of Cu and Fe Oxide Clusters with an Alumina Support for Low-Temperature Catalytic Oxidation of Volatile Organic Compounds.

A γ-alumina support functionalized with transition metals is one of the most widely used industrial catalysts for the total oxidation of volatile organic compounds (VOCs) as air pollutants at higher temperatures (280-450 °C). By rational design of a bimetal CuFe-γ-alumina catalyst, synthesized from a dawsonite alumina precursor, the activity in total oxidation of toluene as a model VOC at a lower temperature (200-380 °C) is achieved. A fundamental understanding of the catalyst and the reaction mechanism is elucidated by advanced microscopic and spectroscopic characterizations as well as by temperature-programmed surface techniques.

Complex magnetism of single-crystalline AlCoCrFeNi nanostructured high-entropy alloy.

We have investigated magnetism of the AlCoCrFeNi single-crystalline high-entropy alloy. The material is nanostructured, composed of a B2 matrix with dispersed spherical-like A2 nanoparticles of average diameter 64 nm. The magnetism was studied from 2 to 400 K via direct-current magnetization, hysteresis curves, alternating-current magnetic susceptibility, and thermoremanent magnetization time decay, to determine the magnetic state that develops in this highly structurally and chemically inhomogeneous material.

Nanotubular TiO N -Supported Ir Single Atoms and Clusters as Thin-Film Electrocatalysts for Oxygen Evolution in Acid Media.

A versatile approach to the production of cluster- and single atom-based thin-film electrode composites is presented. The developed TiO N -Ir catalyst was prepared from sputtered Ti-Ir alloy constituted of 0.8 ± 0.

Design and degradation of permanently porous vitamin C and zinc-based metal-organic framework.

Bioapplication is an emerging field of metal-organic frameworks (MOF) utilization, but biocompatible MOFs with permanent porosity are still a rarity in the field. In addition, biocompatibility of MOF constituents is often overlooked when designing bioMOF systems, intended for drug delivery. Herein, we present the a Zn(II) bioMOF based on vitamin C as an independent ligand (bioNICS-1) forming a three-dimensional chiral framework with permanent microporosity.

Iridium Stabilizes Ceramic Titanium Oxynitride Support for Oxygen Evolution Reaction.

Decreasing iridium loading in the electrocatalyst presents a crucial challenge in the implementation of proton exchange membrane (PEM) electrolyzers. In this respect, fine dispersion of Ir on electrically conductive ceramic supports is a promising strategy. However, the supporting material needs to meet the demanding requirements such as structural stability and electrical conductivity under harsh oxygen evolution reaction (OER) conditions.

Utilisation of waste Cu-, Mn- and Fe-loaded zeolites generated after wastewater treatment as catalysts for air treatment.

Disposal of copper, manganese and iron is particularly problematic in wastewater of metallurgical and galvanization plants, the electronics industry and agriculture. On the other hand, volatile organic compounds (VOCs), emitted from industrial processes, transportation and consumer products are the main class of air pollutants. The study revealed the potential of waste metal-loaded zeolite, generated through wastewater treatment procedures, to be utilised as an effective VOC removal catalyst for air treatment.

Atomic-Level Response of the Domain Walls in Bismuth Ferrite in a Subcoercive-Field Regime.

The atomic-level response of zigzag ferroelectric domain walls (DWs) was investigated with in situ bias scanning transmission electron microscopy (STEM) in a subcoercive-field regime. Atomic-level movement of a single DW was observed. Unexpectedly, the change in the position of the DW, determined from the atomic displacement, did not follow the position of the strain field when the electric field was applied.

Insight into the interdependence of Ni and Al in bifunctional Ni/ZSM-5 catalysts at the nanoscale.

Catalyst design is crucial for improving catalytic activity and product selectivity. In a bifunctional Ni/ZSM-5 zeolite type catalyst, catalytic properties are usually tuned varying Al and Ni contents. While changes in acid properties associated with Al sites are usually closely investigated, Ni phases, however, receive inadequate attention.

Formation of contact and multiple cyclic cassiterite twins in SnO-based ceramics co-doped with cobalt and niobium oxides.

Contact and multiple cyclic twins of cassiterite commonly form in SnO-based ceramics when SnO is sintered with small additions of cobalt and niobium oxides (dual doping). In this work, it is shown that the formation of twins is a two-stage process that starts with epitaxial growth of SnO on CoNbO and CoNbO seeds (twin nucleation stage) and continues with the fast growth of (101) twin contacts (twin growth stage). Both secondary phases form below the temperature of enhanced densification and SnO grain growth; CoNbO forms at ∼700°C and CoNbO at ∼900°C.

Charge Configuration Memory Devices: Energy Efficiency and Switching Speed.

Current trends in data processing have given impetus for an intense search of new concepts of memory devices with emphasis on efficiency, speed, and scalability. A promising new approach to memory storage is based on resistance switching between charge-ordered domain states in the layered dichalcogenide 1T-TaS. Here we investigate the energy efficiency scaling of such charge configuration memory (CCM) devices as a function of device size and data write time τ as well as other parameters that have bearing on efficient device operation.

Revealing the Pb Whisker Growth Mechanism from Al-Alloy Surface and Morphological Dependency on Material Stress and Growth Environment.

Spontaneous metallic Pb whisker formation from Pb and Bi containing Al-alloy's surfaces is a newly discovered phenomenon. The whiskers display unique formations, growth and morphology, which give the opportunity to be applied for specialized sensor and electronics applications. Within this work, the impact of environmental conditions (gas composition and moisture) is investigated and correlated with the modification of whisker evolution and growth dynamics.

Evidence of a 2D Electron Gas in a Single-Unit-Cell of Anatase TiO (001).

The formation and the evolution of electronic metallic states localized at the surface, commonly termed 2D electron gas (2DEG), represents a peculiar phenomenon occurring at the surface and interface of many transition metal oxides (TMO). Among TMO, titanium dioxide (TiO ), particularly in its anatase polymorph, stands as a prototypical system for the development of novel applications related to renewable energy, devices and sensors, where understanding the carrier dynamics is of utmost importance. In this study, angle-resolved photo-electron spectroscopy (ARPES) and X-ray absorption spectroscopy (XAS) are used, supported by density functional theory (DFT), to follow the formation and the evolution of the 2DEG in TiO thin films.

The Effect of the 3D Nanoarchitecture and Ni-Promotion on the Hydrogen Evolution Reaction in MoS /Reduced GO Aerogel Hybrid Microspheres Produced by a Simple One-Pot Electrospraying Procedure.

The transition toward renewable energy sources requires low-cost, efficient, and durable electrocatalysts for green H production. Herein, an easy and highly scalable method to prepare MoS nanoparticles embedded in 3D partially reduced (pr) graphene oxide (GO) aerogel microspheres (MoS /prGOAMs) with controlled morphology and composition is described. Given their peculiar center-diverging mesoporous structure, which allows easy access to the active sites and optimal mass transport, and their efficient electron transfer facilitated by the intimate contact between the MoS and the 3D connected highly conductive pr-GO sheets, these materials exhibit a remarkable electrocatalytic activity in the hydrogen evolution reaction (HER).