Abstract: Sunlight-driven hydrogen production via photoreforming of aqueous solutions containing renewable compounds is an attractive option for sustainable energy generation with reduced carbon footprint. Nevertheless, the absence of photocatalysts combining high efficiency and stability upon solar light activation has up to date strongly hindered the development of this technology. Herein, two scarcely investigated iron(III) oxide polymorphs, β- and ε-Fe2O3, possessing a remarkable activity in sunlight-activated H2 generation from aqueous solutions of renewable oxygenates (i.e., ethanol, glycerol, glucose) are reported. For β-Fe2O3 and ε-Fe2O3, H2 production rates up to 225 and 125 mmol h−1 m−2 are obtained, with significantly superior performances with respect to the commonly investigated α-Fe2O3.

Abstract: Now they are 10! The title compound displays a new type of crystal structure and is labeled clathrate X according to the general classification of clathrate structures. In contrast to typical clathrates, this compound has three-coordinate atoms within the framework and combines distorted 24-vertex polyhedra (see picture, green) centered around tellurium guest atoms with very irregular 10-vertex polyhedra around sulfur atoms (yellow).

Abstract: High pressure high temperature (HPHT) nanodiamonds (NDs) represent extremely promising materials for construction of fluorescent nanoprobes and nanosensors. However, some properties of bare NDs limit their direct use in these applications: they precipitate in biological solutions, only a limited set of bio-orthogonal conjugation techniques is available and the accessible material is greatly polydisperse in shape. In this work, we encapsulate bright 30-nm fluorescent nanodiamonds (FNDs) in 1020-nm thick translucent (i.e., not altering FND fluorescence) silica shells, yielding monodisperse near-spherical particles of mean diameter 66 nm. High yield modification of the shells with PEG chains stabilizes the particles in ionic solutions, making them applicable in biological environments. We further modify the opposite ends of PEG chains with fluorescent dyes or vectoring peptide using click chemistry. High conversion of this bio-orthogonal coupling yielded circa 2000 dye or peptide molecules on a single FND. We demonstrate the superior properties of these particles by in vitro interaction with human prostate cancer cells: while bare nanodiamonds strongly aggregate in the buffer and adsorb onto the cell membrane, the shell encapsulated NDs do not adsorb nonspecifically and they penetrate inside the cells.

Abstract: PECVD of a nanoscale SiO2 capping layer using low pressure SiCl4/O-2/Ar plasmas is numerically investigated. The purpose of this capping layer is to restore photoresist profiles with improved line edge roughness. A 2D plasma and Monte Carlo feature profile model are applied for this purpose. The deposited films are calculated for various operating conditions to obtain a layer with desired shape. An increase in pressure results in more isotropic deposition with a higher deposition rate, while a higher power creates a more anisotropic process. Dilution of the gas mixture with Ar does not result in an identical capping layer shape with a thickness linearly correlated to the dilution. Finally, a substrate bias seems to allow proper control of the vertical deposition rate versus sidewall deposition as desired.

Abstract: Gallium oxide nanorods with unprecedented small dimensions (20-80nm length and 3-5nm width) were prepared using a novel, template-free synthesis method. This nanomaterial is an excellent heterogeneous catalyst for the sustainable epoxidation of alkenes with H2O2, rivaling the industrial benchmark microporous titanosilicate TS-1 with linear alkenes and being much superior with bulkier substrates. A thorough characterization study elucidated the correlation between the physicochemical properties of the gallium oxide nanorods and their catalytic performance, and underlined the importance of the nanorod morphology for generating a material with high specific surface area and a high number of accessible acid sites.

Abstract: It is demonstrated that glycogen as a biodegradable and inexpensive material coming from renewable resources can be used as a carrier for the construction of in vivo imaging nanoagents. The model system considered is composed of glycogen modified with gadolinium and fluorescent labels. Systematic studies of properties of these nanocarriers by a variety of physical methods and results of in vivo tests of biodegradability are reported. This represents, to the authors' best knowledge, the first such use of glycogen.

Abstract: An oxide semiconductor (perovskite-type Mn2O3) is reported which has a narrow and direct bandgap of 0.45 eV and a high Vickers hardness of 15 GPa. All the known materials with similar electronic band structures (e.g., InSb, PbTe, PbSe, PbS, and InAs) play crucial roles in the semiconductor industry. The perovskite-type Mn2O3 described is much stronger than the above semiconductors and may find useful applications in different semiconductor devices, e.g., in IR detectors.

Abstract: Reactive molecular dynamics simulations are performed to study the interaction of reactive oxygen species, such as OH, HO2 and H2O2, with the endotoxic biomolecule lipid A of the gram-negative bacterium Escherichia coli. It is found that the aforementioned plasma species can destroy the lipid A, which consequently results in reducing its toxic activity. All bond dissociation events are initiated by hydrogen-abstraction reactions. However, the mechanisms behind these dissociations are dependent on the impinging plasma species, i.e. a clear difference is observed in the mechanisms upon impact of HO2 radicals and H2O2 molecules on one hand and OH radicals on the other hand. Our simulation results are in good agreement with experimental observations.

Abstract: In this work, we demonstrate the successful incorporation of pure fullerene from solution into two-dimensional layered aluminosilicate minerals. Pure fullerenes are insoluble in water and neutral in terms of charge, hence they cannot be introduced into the clay galleries by ion exchange or intercalation from water solution. To overcome this bottleneck, we organically modified the clay with quaternary amines by using well-established reactions in clay science in order to expand the interlayer space and render the galleries organophilic. During the reaction with the fullerene solution, the organic solvent could enter into the clay galleries, thus transferring along the fullerene molecules. Furthermore, we demonstrate that the surfactant molecules, can be selectively removed by either simple ion-exchange reaction (e.g., interaction with Al(NO3)3 solution to replace the surfactant molecules with Al3+ ions) or thermal treatment (heating at 350 °C) to obtain novel fullerene-pillared clay structures exhibiting enhanced surface area. The synthesized hybrid materials were characterized in detail by a combination of experimental techniques including powder X-ray diffraction, transmission electron microscopy, X-ray photoemission, and UV/Vis spectroscopy as well as thermal analysis and nitrogen adsorptiondesorption measurements. The reported fullerene-pillared clay structures constitute a new hybrid system with very promising potential for the use in areas such as gas storage and/or gas separation due to their high surface area.

Abstract: Si(100)-supported Fe2O3 nanomaterials were developed by a chemical vapor deposition (CVD) approach. The syntheses, which were performed at temperatures between 400 and 550 °C, selectively yielded the scarcely studied β- and ϵ-Fe2O3 polymorphs under O2 or O2 + H2O reaction environments, respectively. Correspondingly, the observed morphology underwent a progressive evolution from interconnected nanopyramids to vertically aligned nanorods. The present study aims to provide novel insights into Fe2O3 nano-organization by a systematic investigation of the system structure/morphology and of their interrelations with growth conditions. In particular, for the first time, the β- and ϵ-Fe2O3 preparation process has been accompanied by a thorough multitechnique investigation, which, beyond X-ray photoelectron spectroscopy (XPS) and field-emission scanning electron microscopy (FESEM), is carried out by X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDXS), atomic force microscopy (AFM), high-resolution transmission electron microscopy (HRTEM), electron diffraction (ED), scanning TEM electron energy-loss spectroscopy (STEM-EELS), and high-angle annular dark-field STEM (HAADF-STEM). Remarkably, the target materials showed a high structural and compositional homogeneity throughout the whole thickness of the nanodeposit. In particular, spatially resolved EELS chemical maps through the spectrum imaging (SI) technique enabled us to gain important information on the local Fe coordination, which is of crucial importance in determining the system reactivity. The described preparation method is in fact a powerful tool to simultaneously tailor phase composition and morphology of iron(III) oxide nanomaterials, the potential applications of which include photocatalysis, magnetic devices, gas sensors, and anodes for Li-ion batteries.

Abstract: A crucial step, which is still not well understood in the destruction of volatile organic compounds (VOCs) with low temperature plasmas, is the initiation of the process. Here, we present a kinetic model for the destruction of ethylene in low temperature plasmas that allows us to calculate the relative importance of all plasma species and their related reactions. Modifying the ethylene concentration and/or the SED had a major impact on the relative importance of the radicals (i.e., mainly atomic oxygen) and the metastable nitrogen (i.e., more specifically N2(equation image)) in the destruction process. Our results show that the direct destruction by electron impact reactions for ethylene can be neglected; however, we can certainly not neglect the influence of N2(equation image)).

Abstract: Tuning the lattice degree of freedom in nanoscale functional crystals is critical to exploit the emerging functionalities such as piezoelectricity, shape-memory effect, or piezomagnetism, which are attributed to the intrinsic lattice-polar or lattice-spin coupling. Here it is reported that a mechanical probe can be a dynamic tool to switch the ferroic orders at the nanoscale multiferroic phase boundaries in BiFeO3 with a phase mixture, where the material can be reversibly transformed between the soft tetragonal-like and the hard rhombohedral-like structures. The microscopic origin of the nonvolatile mechanical switching of the multiferroic phase boundaries, coupled with a reversible 180 degrees rotation of the in-plane ferroelectric polarization, is the nanoscale pressure-induced elastic deformation and reconstruction of the spontaneous strain gradient across the multiferroic phase boundaries. The reversible control of the room-temperature multiple ferroic orders using a pure mechanical stimulus may bring us a new pathway to achieve the potential energy conversion and sensing applications.