Riversmunck5202

Z Iurium Wiki

Ln(iii) complexes are not only capable of efficient CO2 capture via reversible insertion but also of CO2 activation for catalytic conversions (copolymerization/cycloaddition with epoxides). This perspective focuses on structurally elucidated Ln complexes resulting from ketone or carbonyl derivative activation/insertion as well as carbon dioxide insertion products. The respective compounds will be sorted by structural motifs and, if applicable, details on reactivity and feasibility of catalytic reactions are presented. The article is subdivided in three parts (i) donor and insertion products of ketones and aldehydes, (ii) redox-enhanced activation of carbonyl derivatives, and (iii) CO2 insertion/redox products and homogeneous catalytic conversion.The combination of black TiO2 nanoparticles (NPs) with a nickel catalyst provides a low-cost, sustainable, and reusable alternative dual catalytic system to a homogeneous counterpart (noble metals). This black TiO2-photoredox/nickel dual catalytic system has efficiently driven C-P bond formation between aryl iodides and diarylphosphine oxides under visible light, providing good to excellent yields as well as tolerating a variety of functional groups. The practical application of this semi-heterogeneous protocol has been highlighted by a sunlight experiment, a gram-scale reaction, and a reusability test.Due to the considerable interest in vanadium niobium oxides as a lithium storage material, the kinetics and transformation processes of the V2O5-5Nb2O5 system have been investigated by in situ synchrotron powder X-ray diffraction. The diffraction data after the thermal treatments selected with a view on the most significant features were supplemented with specific ex situ experiments conducted using a laboratory rotating anode X-ray diffractometer. The morphological changes of the mixed powders assuming an amorphous and nanocrystalline solid solution structure as a function of the temperature were inspected by scanning electron microscopy observations. The structural solution of the powder diffraction pattern of the phase recorded in situ at a temperature of about 700 °C was compatible with an orthorhombic crystal structure with the space group Amm2. The obtained lattice parameters for this structure were a = 3.965 Å; b = 17.395 Å, c = 17.742 Å, and the cell composition was V4Nb20O60, Pearson symbol oA84, and density = 4.10 g cm-3. In this structure, while the niobium atoms may be four-, five-, and six-fold coordinated by oxygen atoms, the vanadium atoms were six-fold or seven-fold coordinated. At the temperature of 800 °C and just above, the selected 1  2 and 1  3 V2O5-Nb2O5 compositions, respectively, returned mostly a tetragonal VNb9O25 phase, in line with earlier observations conducted for determination of the stability phase diagram of such quasi-binary systems.Elemental doping of hematite has been widely performed to improve its mobility, electrical conductivity as well as to suppress electron-hole recombination in photoelectrochemical applications. When hematite is doped with high titanium concentrations, above 5%, pseudobrookite layers may be formed as overlayers leading to improved photocurrent while further doping beyond 15% could lead to the formation of a titania overlayer which has an effect of suppressing photocurrent. In this study, we observed that doping hematite with titanium improves photocurrent, reaching a maximum of 1.83 mA cm-2 at a titanium concentration of 15%, the highest achieved photocurrent with spin coating method. Further titanium incorporation to 20% resulted in a decrease of the photocurrent. XRD measurements shows that a Fe2TiO5 layer formed at 15% Ti concentration which resulted in the observed increase in photocurrent while a reduction in photocurrent at 20% Ti concentration could have resulted from the formation of a TiO2 layer. Analysis of the transient absorption spectroscopy data was achieved using a four-component sequential analysis scheme in the Glotaran software. We observed major doping concentration dependent lifetimes in the τ3 and τ4 values where the 15% doped samples had the slowest recombination rates. We also observed a blueshift in the spectra with increasing doping concentration, suggesting the occurance of the Burstein-Moss effect. This work shows that doping hematite with titanium leads to structural changes of the photoanodes at Ti concentrations of over 10%, in addition to the well documented conductivity enhancement.Magnetic materials attract great attention due to their fundamental importance and practical application. However, the relatively inferior mechanical properties of traditional magnetic materials limit their application in a harsh environment. In this work, we report an outstanding magnetic material that exhibits both fantastic mechanical and excellent magnetic properties, CuAl2-type Fe2B, synthesized by the high pressure and high temperature method. The magnetic saturation of Fe2B is 156.9 emu g-1 at room temperature and its Vickers hardness is 12.4 GPa which outclasses those of traditional magnetic materials. It exhibits good conductivity with a resistivity of 5.6 × 10-7 Ω m. Fe2B is a promising strong ferromagnetic material with high hardness, which makes it a good candidate for multifunction applications in a harsh environment. HRS-4642 mouse The high hardness of Fe2B originates from the Fe-B bond framework, and the strong ferromagnetism is mainly attributed to the large number of unpaired Fe 3d electrons. The competition of Fe 3d electrons to fall into Fe-B bonds or Fe-Fe bonds is the main factor for its magnetism and hardness. This work bridges the chasm between strong ferromagnetism and high hardness communities.Low-dimensional materials have aroused widespread interest for their novel and fascinating properties. Based on first-principles calculations, we predict the one-dimensional (1D) InSeI nanochains with van der Waals (vdW) interchain interactions, which could be exfoliated mechanically and kept at steady states at room temperature. Compared with bulk InSeI, the single nanochain InSeI has a larger direct bandgap of 3.15 eV. Its calculated carrier mobility is as high as 54.17 and 27.49 cm2 V-1 s-1 for holes and electrons, respectively, comparable with those of other 1D materials. In addition, a direct-to-indirect bandgap transition is implemented under a small applied strain (∼6%). More importantly, the nanochains are found to be promising candidates for optoelectronic devices since they possess a high absorption coefficient of ∼105 cm-1 in the ultraviolet region. The results thus pave a novel avenue for the applications of InSeI nanochains with excellent thermal stability in nanoelectronic and optoelectronic devices.

Autoři článku: Riversmunck5202 (McWilliams Hinrichsen)