Hierarchically Porous Fe-N-C Single-Atom Catalysts via Ionothermal Synthesis for Oxygen Reduction Reaction.

Platinum group metal (PGM)-free electrocatalysts have emerged as promising alternatives to replace Pt for the oxygen reduction reaction (ORR) in anion exchange membrane fuel cells (AEMFCs). However, traditional synthesis methods limit the single-atom site density due to metal agglomeration at higher temperatures. This work explores the preparation of hierarchically porous atomically dispersed electrocatalysts for the ORR.

Reusable magnetic mixture of CuFeO-FeO and TiO for photocatalytic degradation of pesticides in water.

Photocatalysis is a promising treatment method to remove pollutants from water. TiO-P25 is a commercially available model photocatalyst, which very efficiently degrades organic pollutants under UVA light exposure. However, the collection and the recovery of TiO-P25 from cleaned water poses significant difficulties, severely limiting its usability.

Comparison of Toxicity and Cellular Uptake of CdSe/ZnS and Carbon Quantum Dots for Molecular Tracking Using as a Fungal Model.

Plant resource sharing mediated by mycorrhizal fungi has been a subject of recent debate, largely owing to the limitations of previously used isotopic tracking methods. Although CdSe/ZnS quantum dots (QDs) have been successfully used for in situ tracking of essential nutrients in plant-fungal systems, the Cd-containing QDs, due to the intrinsic toxic nature of Cd, are not a viable system for larger-scale in situ studies. We synthesized amino acid-based carbon quantum dots (CQDs; average hydrodynamic size 6 ± 3 nm, zeta potential -19 ± 12 mV) and compared their toxicity and uptake with commercial CdSe/ZnS QDs that we conjugated with the amino acid cysteine (Cys) (average hydrodynamic size 308 ± 150 nm, zeta potential -65 ± 4 mV) using yeast as a proxy for mycorrhizal fungi.

Cobalt Phthalocyanine-Doped Polymer-Based Electrocatalyst for Rechargeable Zinc-Air Batteries.

Rechargeable zinc-air batteries (RZAB) have gained significant attention as potential energy storage devices due to their high energy density, cost-effectiveness, and to the fact that they are environmentally safe. However, the practical implementation of RZABs has been impeded by challenges such as sluggish oxygen reduction reaction (ORR) and oxygen evolution reaction (OER), including poor cyclability. Herein, we report the preparation of cobalt- and nitrogen-doped porous carbon derived from phloroglucinol-formaldehyde polymer networks with 2-methyl imidazole and cobalt phthalocyanine as precursors for nitrogen and cobalt.

Nanostructures Stacked on Hafnium Oxide Films Interfacing Graphene and Silicon Oxide Layers as Resistive Switching Media.

SiO films were grown to thicknesses below 15 nm by ozone-assisted atomic layer deposition. The graphene was a chemical vapor deposited on copper foil and transferred wet-chemically to the SiO films. On the top of the graphene layer, either continuous HfO or SiO films were grown by plasma-assisted atomic layer deposition or by electron beam evaporation, respectively.

Memory Effects in Nanolaminates of Hafnium and Iron Oxide Films Structured by Atomic Layer Deposition.

HfO and FeO thin films and laminated stacks were grown by atomic layer deposition at 350 °C from hafnium tetrachloride, ferrocene, and ozone. Nonlinear, saturating, and hysteretic magnetization was recorded in the films. Magnetization was expectedly dominated by increasing the content of FeO.

Transition-Metal- and Nitrogen-Doped Carbide-Derived Carbon/Carbon Nanotube Composites as Cathode Catalysts for Anion-Exchange Membrane Fuel Cells.

Transition-metal- and nitrogen-codoped carbide-derived carbon/carbon nanotube composites (M-N-CDC/CNT) have been prepared, characterized, and used as cathode catalysts in anion-exchange membrane fuel cells (AEMFCs). As transition metals, cobalt, iron, and a combination of both have been investigated. Metal and nitrogen are doped through a simple high-temperature pyrolysis technique with 1,10-phenanthroline as the N precursor.

Nanoindentation of Chromium Oxide Possessing Superior Hardness among Atomic-Layer-Deposited Oxides.

Chromium (III) oxide is a technologically interesting material with attractive chemical, catalytic, magnetic and mechanical properties. It can be produced by different chemical and physical methods, for instance, by metal-organic chemical vapor deposition, thermal decomposition of chromium nitrate Cr(NO) or ammonium dichromate (NH)CrO, magnetron sputtering and atomic layer deposition. The latter method was used in the current work to deposit CrO thin films with thicknesses from 28 to 400 nm at deposition temperatures from 330 to 465 °C.

Atomic layer deposition of superparamagnetic ruthenium-doped iron oxide thin film.

Due to the several applications of biosensors, such as magnetic hyperthermia and magnetic resonance imaging, the use of superparamagnetic nanoparticles or thin films for preparing biosensors has increased greatly. We report herein on a strategy to fabricate a nanostructure composed of superparamagnetic thin films. Ruthenium-doped iron oxide thin films were deposited by using atomic layer deposition at 270 and 360 °C.

Magnetic and Electrical Performance of Atomic Layer Deposited Iron Erbium Oxide Thin Films.

Mixed films of a high-permittivity oxide, ErO, and a magnetic material, FeO, were grown by atomic layer deposition on silicon and titanium nitride at 375 °C using erbium diketonate, ferrocene, and ozone as precursors. Crystalline phases of erbium and iron oxides were formed. Growth into three-dimensional trenched structures was demonstrated.

Graphene Nanoplatelets Based Protective and Functionalizing Coating for Stainless Steel.

Stainless steel is the most widely used alloy for many industrial and everyday applications, and protection of this alloy substrate against corrosion is an important industrial issue. Here we report a promising application of graphene oxide and graphene nanoplatelets as effective corrosion inhibitors for AISI type 304 stainless steel alloy. The graphene oxide and graphene coatings on the stainless steel substrates were prepared using spin coating techniques.

Functionalization of Titanium Alloy Surface by Graphene Nanoplatelets and Metal Oxides: Corrosion Inhibition.

Corrosion inhibition of metallic substrates is an important and crucial step for great economical as well as environmental savings. In this paper, we introduce an extra thin effective corrosion inhibitive material having layered structure designed for protection and functionalization of Ti Grade 5 alloy substrates. The coating consists of a first layer made of thin graphene nanoplatelets, on top of which a multilayer Al2O3 and TiO2 films is applied by low-temperature atomic layer deposition.

Electrospun nanofibers as a potential controlled-release solid dispersion system for poorly water-soluble drugs.

Electrospinning was introduced as a novel technique for preparing controlled-release (CR) amorphous solid dispersions (SD) and polymeric nanofibers of a poorly water-soluble drug. Piroxicam (PRX) was used as a low-dose poorly-soluble drug and hydroxypropyl methylcellulose (HPMC) as an amorphous-state stabilising carrier polymer in nanofibers. Raman spectroscopy, X-ray powder diffraction (XPRD), differential scanning calorimetry (DSC) and scanning electron microscopy (SEM) were used in the physical characterisation of the CR-SD nanofibers.

Nanometer depth resolution in 3D topographic analysis of drug-loaded nanofibrous mats without sample preparation.

We showed that scanning white light interferometry (SWLI) can provide nanometer depth resolution in 3D topographic analysis of electrospun drug-loaded nanofibrous mats without sample preparation. The method permits rapidly investigating geometric properties (e.g.

Water-mediated solid-state transformation of a polymorphic drug during aqueous-based drug-layer coating of pellets.

During aqueous drug-layer coating, drug substance(s) are exposed to water and elevated temperatures which can lead to water-mediated process induced transformations (PITs). The effects of aqueous drug-layer coating of pellets (Cellets(®)) on the anhydrous piroxicam, PRX, were investigated in the miniaturized coating equipment and with free films. Hydroxypropyl methylcellulose (HPMC) was used as a carrier coating polymer.