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The surface properties of nickel-based alloys with different alloying compositions against aggressively corrosive species were systematically evaluated by using the segregated and non-segregated models designed through first-principles calculations. The presence of typical VIB alloying elements such as chromium (Cr), molybdenum (Mo), and tungsten (W) elements near the nickel surface was identified to significantly enhance the surface adsorption of water molecules (H2O) and their decomposed products (OH, O, and H). The doping patterns and surface electronic structures were found to determine the adsorption diversity of these substances. Consequently, adsorbates containing oxygen were likely to induce the segregation tendencies of these selected alloying elements from the deep area of nickel toward the top-most surface layer (TSL). The electrode potential shifts of the surface Ni atom in the designed alloying systems, compared to the bare Ni (111) surface, were further calculated to identify the beneficial electrochemical performance of alloy surfaces in the absence/presence of various adsorbates. In vacuum, the locations of these alloying elements in the near-surface layers would more increase the electrode potential shifts, thereby delaying the dissolution of Ni atoms from metal substrates. Nevertheless, the presence of adsorbates led to notably negative electrode potential shifts for the Ni (111) surface, among which the decomposed products (hydroxyl and oxygen) were of the most passive effects on corrosion behavior of nickel. The detrimental effects of these adsorbates on surface stability would be effectively alleviated with the aid of atomic VIB alloying elements of nickel-based alloys, especially W segregation to the TSL regardless of the pH in aqueous environments. [ABSTRACT FROM AUTHOR]

By electric transport measurements on high-purity bulk molybdenum single crystals at helium-temperature, it is shown that when approaching the ideal metallic crystal structure, there are deviations from Ohm's law that can exceed 30% even at low current densities ≅ 3 A / m m 2. This is due to the intrinsic circular magnetic field of the measuring current in the range of B ≅ 1 mT , which generates a magnetoresistance according to the two-band conduction model. With increasing lattice vibrations and/or crystal defects, this inherent uncertainty finally reduces to immeasurably small values. Finally, Ohm's law for a nearly ideal lattice structure can be strictly exact only in the theoretical limiting case of an infinite lattice plane, because then the magnetic fields of all electrons of the current compensate to zero. [ABSTRACT FROM AUTHOR]

Since the form of the exact functional in density functional theory is unknown, we must rely on density functional approximations (DFAs). In the past, very promising results have been reported by combining semi-local DFAs with exact, i.e. Hartree–Fock, exchange. However, the spin-state energy ordering and the predictions of global minima structures are particularly sensitive to the choice of the hybrid functional and to the amount of exact exchange. This has been already qualitatively described for single conformations, reactions, and a limited number of conformations. Here, we have analyzed the mixing of exact exchange in exchange functionals for a set of several hundred isomers of the transition metal carbide, Mo4C2. The analysis of the calculated energies and charges using PBE0-type functional with varying amounts of exact exchange yields the following insights: (1) The sensitivity of spin-energy splitting is strongly correlated with the amount of exact exchange mixing. (2) Spin contamination is exacerbated when correlation is omitted from the exchange-correlation functional. (3) There is not one ideal value for the exact exchange mixing which can be used to parametrize or choose among the functionals. Calculated energies and electronic structures are influenced by exact exchange at a different magnitude within a given distribution; therefore, to extend the application range of hybrid functionals to the full periodic table the spin-energy splitting energies should be investigated. [ABSTRACT FROM AUTHOR]

This paper presents the experimental evidence of reversible insulator–metal transition (IMT) in thin-film amorphous molybdenum trioxide (MoO3) induced by electric fields of just a few volts. The presence of oxygen vacancies in MoO3 is considered to play a significant role in the reported reversible IMT. The oxygen vacancies not only impact MoO3 stoichiometry but also the optical bandgap. The subthreshold slope for IMT in 10 nm-thick MoO3-based devices is 48.3 mV/decade, which represents a transition from an insulator to a metallic state, and the electric field threshold for such a transition was found to be equal to 0.034 V/Å. Following the IMT in MoO3, there are six orders of magnitude differences between the resistivity of the insulator state (27.5 M Ω at −9 V) and the metallic state (80 Ω between +5 and +9 V). In addition, we reported stabilization of a nanocrystalline hexagonal MoO3 (h-MoO3) phase in thicker MoO3 (150 nm-thick) in the presence of oxygen vacancies that behave as a wide bandgap (3.1 eV) ferroelectric semiconductor with a coercive field of about 50 kV/cm, a saturation polarization of about 30 μC/cm2, and a remanent polarization of about 10 μC/cm2. This ferroelectricity in nanocrystalline h-MoO3 (150 nm-thick) remains stable even after 8 months of storage of the sample in ambient conditions, with remanent polarization increasing up to 20 μC/cm2. These are unexpected results from MoO3. [ABSTRACT FROM AUTHOR]

The synthesis and characterization of two bis(dithiolene) proligands involving heteroatomic linkers such as 1,4-dithiine and dihydro-1,4-disiline between the two protected dithiolene moieties are described. Two bimetallic complexes involving these heteroatomic bridges between two redox active bis(cyclopentadienyl)molybdenum dithiolene moieties have been synthesized and characterized by electrochemistry, spectroelectrochemistry, and their properties rationalized with (TD-)DFT. Cyclic voltammetry experiments show sequential oxidation of the two redox centers with ΔE values between successive one-electron transfers varying according to the nature of the bridge. Depending on the nature of the heteroatomic bridge, the bis-oxidized complexes exhibit either a diradical character with both radicals essentially localized on the metallacycles, or a closed-shell dicationic state. [ABSTRACT FROM AUTHOR]

Molybdenum tailings (MTs) and kaolinite were used as the main materials in the fabrication ceramic foams (CFs) via the high-temperature sintering method, with the addition of SiC as a foaming agent. The effects of MT content on the basic physical properties, pore structure, and chemical characterization were investigated. Results showed that MT enhanced the foaming capability. When the MT content was 60% and the sintering temperature was 1170 °C, the optimum CFs obtained demonstrated bulk density, porosity, water absorption, and compressive strength of 0.55 g/cm3, 77.3%, 6.94%, and 6.74 MPa, respectively, and the pore structure was relatively homogeneous with an average pore diameter of 0.67 mm. The results revealed that SiO 2 –-Al 2 O 3 –-MgO–-CaO system CFs can be prepared from Ca–Mg-rich MT, which provided a feasible strategy for value-added utilization of Ca–Mg-rich MT. [ABSTRACT FROM AUTHOR]

MoS2 and WS2 are spotlighted as fungible materials of graphene that can be used in electronic devices owing to being semiconductors with indirect and direct band gaps. Precursors (Mo(NtBu)2(StBu)2 (1), W(NtBu)2(StBu)2 (2)) suitable for the deposition of these materials were synthesized and characterized. The molecular structures of 1 and 2 exhibit a tetrahedral geometry according to single‐crystal x‐ray crystallography. Thermogravimetric analyses of 1 and 2 showed two‐step weight loss. The residues from each step of 1 were MoS3 and MoS2, and these results were consistent with the subsequent deposition results of 1. We successfully established a PEALD‐MoS2 process using 1 and H2S plasma as the precursor and reactant, respectively, at relatively low temperatures of 150–300 °C without any post‐sulfurization process. A temperature‐dependent selective deposition of MoSx phases was observed with the growth of amorphous MoS3 films (150–200 °C), and crystalline MoS2 films (250–350 °C). [ABSTRACT FROM AUTHOR]

In this study, BiMeVOx compounds (where Me: Co, Mo, Ce, Zr) were synthesized and characterized as potential photoelectrochemical materials for solar water splitting, the hydrogen evolution reaction (HER), and oxygen evolution reaction (OER). The analysis confirmed the successful formation of phase BiMeVOx compounds with the desired crystal structure. Among the tested materials, BiCoVOx(800) showed the highest photocurrent density (674 μA cm−2) and HER/OER activity (Tafel slope: HER = 100 mV dec−1 and OER = 75 mV dec−1), followed by BiMoVOx(800), BiCeVOx(800), and BiZrVOx(800). The superior photoelectrochemical performance of BiCoVOx(800) can be attributed to its unique electronic structure and optimized band alignment, which promote efficient charge separation and facilitate the water splitting and hydrogen evolution processes. The findings of this study highlight the promising potential of the synthesized BiMeVOx materials, particularly BiCoVOx, as efficient photoelectrochemical catalysts for water splitting. These results contribute to the advancement of renewable energy technologies and provide valuable insights for the design and development of novel photoactive materials. [Display omitted] • BiMeVOx (Me: Co, Ce, Mo, Zr) catalysts were synthesized for water electrolysis to produce hydrogen energy. • BiCoVOx(800) as a Bifunctional Catalyst for HER and OER. • The BiCoVOx photoanode shows a photocurrent density of Δj = 674 μA cm−2. • Multifunctional BiCoVOx Enhances Water Splitting. [ABSTRACT FROM AUTHOR]

In this work, Ru nanoparticles doped with Mo on reduced graphene oxide (RuMo/rGO) are prepared through synchronous reduction of RuCl3, MoCl5, and graphene oxide. The compositions, morphologies, and structures of the as-prepared RuMo/rGO composites are fully characterized. Their catalytic properties in oxidative cleavage of β-O-4 linkages in lignin model compounds and lignin are explored. It is illustrated that with O2 as the oxidant RuMo/rGO shows overall better catalytic performance in the oxidative cleavage of β-O-4 linkages than the catalysts, such as Ru/rGO and RuCo/rGO, reported in our previous work. The catalytic mechanism is elaborated through experiments and density functional theory (DFT) calculation. Pronouncedly, we show that the as-doped Mo can effectively boost the molecular oxygen activation process and the adsorption of β-O-4 model compounds on the Ru nanoparticle surface on rGO, and thus enhance the catalytic activity. It is demonstrated meanwhile that RuMo/rGO can catalyze the depolymerization of organosolv birch lignin yielding 17.1% aromatic compounds under relatively mild conditions (100 °C, 0.3 MPa O2, 12 h, pH = 12). [ABSTRACT FROM AUTHOR]

Octanuclear polyoxomolybdenum-based porous materials, Na8[Mo8O8(µ2-O)8(µ2-OH)8(3-apz)4]2·26H2O (1, 3-Hapz = 3-aminopyrazole), K8[Mo8O8(µ2-O)8(µ2-OH)8(3-apz)4]2·7H2O (2) and (NH4)4[Mo8O8(µ2- O)8(µ2-OH)4(3-apz)8]·20.5H2O (3), have been successfully synthesized by a hydrothermal method and fully characterized. X-ray structural analyses show that microporous materials 1-3 contain round pores formed by octanuclear molybdenum-oxygen groups connected sequentially with pore sizes of 4.0, 4.0, and 4.8 Å, respectively. Both 1 and 2 are composed of two {Mo8} rings, which are connected by strong intramolecular hydrogen bonds between bridging hydroxy groups and oxygen atoms to form dimeric structures. The central pores in 1 and 2 are occupied by Na+ and K+, respectively, while they are empty in 3. This reflects the structural expansion and contraction effects induced by different cations. Through intermolecular stacking, 1-3 also exhibit channels with sizes of 14.0 × 6.4, 4.6 × 2.6, and 5.4 × 5.4 Å, respectively, which were used for the studies of gas adsorption. The results show that 1-3 can selectively adsorb CO2 and O2, including the empty hole in 3, while they show little or no affinity for gases H2, N2, and CH4. Moreover, an additional polyoxomolybdenum-based species (Mo8O26)n·4n(3-H2apz) (4) has been obtained with protonated 3-aminopyrazole in the absence of a reducing agent, which can serve as an intermediate for the polyoxomolybdenum-based porous products. [ABSTRACT FROM AUTHOR]

Metal borides have received a lot of attention recently as a potentially useful material for a wide range of applications. In particular, molybdenum‐based borides and MBenes are of great significance, due to their remarkable properties like good electronic conductivity, considerable stability, high surface area, and environmental harmlessness. Therefore, in this article, the progress made in molybdenum‐based borides and MBenes in recent years is reviewed. The first step in understanding these materials is to begin with an overview of their structural and electronic properties. Then synthetic technologies for the production of molybdenum borides, such as high‐temperature/pressure methods, physical vapor deposition (PVD), chemical vapor deposition (CVD), element reaction route, molten salt‐assisted, and selective etching methods are surveyed. Then, the critical performance of these materials in numerous applications like energy storage, catalysis, biosensors, biomedical devices, surface‐enhanced Raman spectroscopy (SERS), and tribology and lubrication are summarized. The review concludes with an analysis of the current progress of these materials and provides perspectives for future research. Overall, this review will offer an insightful reference for the understanding molybdenum‐based borides and their development in the future. [ABSTRACT FROM AUTHOR]

Cobalt molybdenum nitrides can be obtained from the oxidic precursor by reaction with gaseous ammonia. Despite the large number of works regarding the catalytical properties of these compounds, there are relatively few reports about the initial transformation from oxide to nitride. In this work, the influence of the precursor structure on the active phase formation and catalytic properties of cobalt molybdenum nitrides is examined. Oxidic precursors were obtained by precipitation at different pH values controlled by the addition of aqueous ammonia. The parameters of the precipitation process affected the composition and properties of the materials. The ammonolysis of NH4Co2OH(MoO4)2 ⋅ H2O was investigated in situ with the use of X‐ray powder diffraction and thermogravimetry. The ammonia synthesis activity of the obtained catalysts was compared to the reference iron catalyst. The formation of the Co3Mo intermetallic phase was suggested as the factor governing high activity. [ABSTRACT FROM AUTHOR]

Analyzing sulfur (S) and molybdenum (Mo) isotope ratios in molybdenite, the most common sulfide mineral, is crucial for studying the genesis of ore deposits. However, it is necessary to prepare matrix-matched reference materials for molybdenite. In this study, we employed two different techniques, the high-temperature-high-pressure (HTHP) technique and the rapid hot-pressing technique, to synthesize molybdenites and assessed their suitability as reference materials for in situ Mo and S isotope analysis in molybdenite. The molybdenites synthesized through HTHP and rapid hot-pressing exhibit smooth surfaces and dense structures, making them suitable as reference materials for in situ Mo and S isotope analysis, respectively. These synthesized molybdenites exhibit homogeneous Mo and S isotope compositions based on a large number of LA-MC-ICP-MS measurements. The mean δ98MoNIST SRM 3134 values of 0.70 ± 0.06‰ (n = 4, 2SD) and 0.70 ± 0.05‰ (n = 4, 2SD) determined by solution nebulization MC-ICP-MS are suggested as recommended δ98Mo/95Mo values for Mo-H8 and Mo-P. The mean δ34SV-CDT value of −0.22 ± 0.10‰ (n = 9, 2SD) determined by elemental analyzer isotope ratio mass spectrometry (EA-IRMS) is suggested as a recommended δ34S/32S value for Mo-H8 and Mo-P. Therefore, we recommend combining ultrafine powders with a high-temperature–high-pressure technique and/or a rapid hot-pressing technique to synthesize reference materials for isotopic analysis of other minerals. [ABSTRACT FROM AUTHOR]

The structural and electronic properties of pure graphene, graphene with a vacancy, graphene with two vacancies and molybdenum‐doped graphene were investigated. In addition, the adsorption of Mo atoms on graphene (G), reduced graphene (rG) and reduced graphene oxide (rGO) was examined. The possible energies of different active adsorption sites of nanostructured Mo‐decorated G, rG and rGO have been calculated using density functional theory (DFT). Mo atoms are predicted to create bonds with six C atoms in G, three C atoms in rG, and both C and O atoms in rGO sheets after geometry optimizations. The study focused on changing the electronic structure of G, including opening the zero band gap and controlling the band structure, which was done by creating defects and adding impurities. The present study revealed a significant correlation between the adsorption of the Mo atom and the characteristics exhibited by frontier orbitals. The results indicated that the adsorption characteristics of Mo atoms in pure G, rG and rGO are different, despite chemisorption being the common mechanism. Specifically, Mo‐decorated rG exhibited higher adsorption energy, while Mo‐decorated G demonstrated a lower adsorption energy. According to these findings, it is reasonable to anticipate that Mo‐decorated rG could be applied as a novel adsorbent for the removal of pollutants. [ABSTRACT FROM AUTHOR]

Molybdenum cofactor deficiency classically presents in neonates with intractable seizures; however, milder cases generally present before age 2 years with developmental delays and may go undiagnosed. Early diagnosis, and safe, US Food and Drug Administration-approved substrate replacement are critical to preserve neurologic function. This article discusses 2 children who presented with late-onset molybdenum cofactor deficiency type A. [ABSTRACT FROM AUTHOR]

A procedure for the separation of technetium isotopes from bulk molybdenum was developed in nitric acid media. After irradiation of natMo foils, and dissolution in H2O2, the solution is acidified to 2 M HNO3, and anion exchange resin is used to separate technetium from molybdenum. The procedure is simple, requiring only basic laboratory equipment and, with a two-column separation, the technetium yield is high (~ 85%) with extremely high purity (< 0.1 ppm natMo). This is ideally suited for laboratory production of technetium tracer isotopes, particularly 95mTc. [ABSTRACT FROM AUTHOR]

As a high-efficiency electrocatalyst for NH 3 production via NO 2 − reduction, Mo-doped Co 3 O 4 nanoarray exhibits an extremely high Faradaic efficiency of 96.9 % and a corresponding NH 3 yield of up to 651.5 μmol/h cm−2 at −0.5 V. [Display omitted] • Mo-doped Co 3 O 4 nanoarray on titanium mesh is synthesized as an effective catalyst for NO 2 −-to-NH 3 conversion. • Mo-Co 3 O 4 /TM exhibits a high NH 3 Faradaic efficiency of 96.9 % and a related yield of 651.5 μmol h−1 cm−2 with strong stability. • DFT calculations reveal the catalytic mechanism of NO 2 −RR on Mo-Co 3 O 4. • The fabricated Zn-NO 2 − battery achieves a peak power density of 3.6 mW cm−2 and a satisfactory NH 3 yield of 108.4 μmol h−1 cm−2. Electrochemical conversion of nitrite (NO 2 −) contaminant to green ammonia (NH 3) is a promising approach to achieve the nitrogen cycle. The slow kinetics of the complex multi-reaction process remains a serious issue, and there is still a need to design highly effective and selective catalysts. Herein, we report that molybdenum doped cobalt oxide nanoarray on titanium mesh (Mo-Co 3 O 4 /TM) acts as a catalyst to facilitate electroreduction of NO 2 − to NH 3. Such a catalyst delivers an extremely high Faradaic efficiency of 96.9 % and a corresponding NH 3 yield of 651.5 μmol h−1 cm−2 at −0.5 V with strong stability. Density functional theory calculations reveal that the introduction of Mo can induce the redistribution of electrons around Co atoms and further strengthen the adsorption of NO 2 −, which is the key to facilitating the catalytic performance. Furthermore, the assembled battery based on Mo-Co 3 O 4 /TM suggests its practical application value. [ABSTRACT FROM AUTHOR]

We introduce an ultra-wideband absorber with a molybdenum and Al2O3 multilayer structure for solar energy harvesting. The proposed structure could maintain its structural integrity at high temperatures thanks to the refractory materials used in its construction. Under normal incidence of optical waves, absorption of more than 90% is achieved throughout a broad range of wavelengths from 300 nm to approximately 3177 nm with a bandwidth of 2877 nm which covers ultraviolet, visible, and near-infrared spectral bands. The average absorption in that band is calculated to be 96.46%. The proposed design's symmetrical characteristic makes the absorber insensitive to the polarization of the incident optical wave. Furthermore, throughout a broad range of optical wave angles of incidence for both transverse electric and transverse magnetic polarizations, the absorber supports absorptivity greater than 80%. [ABSTRACT FROM AUTHOR]

Molybdenum cofactor sulfurase (MoCoS) is a key gene involved in the uric acid metabolic pathway that activates xanthine dehydrogenase to synthesise uric acid. Uric acid is harmful to mammals but plays crucial roles in insects, one of which is the immune responses. However, the function of Bombyx mori MoCoS in response to BmNPV remains unclear. In this study, BmMoCoS was found to be relatively highly expressed in embryonic development, gonads and the Malpighian tubules. In addition, the expression levels of BmMoCoS were significantly upregulated in three silkworm strains with different levels of resistance after virus infection, suggesting a close link between them. Furthermore, RNAi and overexpression studies showed that BmMoCoS was involved in resistance to BmNPV infection, and its antivirus effects were found to be related to the regulation of uric acid metabolism, which was uncovered by inosine‐ and febuxostat‐coupled RNAi and overexpression. Finally, the BmMoCoS‐mediated uric acid pathway was preliminarily confirmed to be a potential target to protect silkworms from BmNPV infection. Overall, this study provides new evidence for elucidating the molecular mechanism of silkworms in response to BmNPV infection and new strategies for the prevention of viral infections in sericulture. [ABSTRACT FROM AUTHOR]

Extraction of molybdenum (Mo) from jordisite is difficult due to the amorphous state of MoS2. In this study, mechanical activation was employed to pretreat this type of ore with a low Mo content of 0.26%, and then molybdenum and uranium were both extracted from the milled ore using sulfuric acid. The effects of milling time, oxidant, and optimal leaching conditions were investigated in the laboratory. The results show that the mechanical activation will reduce the particle size and increase the specific surface area of the ore under certain milling conditions. Mechanical activation without oxidants in a hypoxia environment is not conductive to the recovery of molybdenum. When the oxidant of MnO2 is added during the milling process, the Mo recovery will increase greatly. The effect of mechanical activation on U recovery is not so obvious. The phenomenon of agglomerate will occur during the milling process, which will reduce Mo recovery seriously, especially when the milling time is more than 120 min. The Mo and U recovery can reach 84.52% and 61.39%, respectively, after optimization of sulfuric acid leaching process conditions. [ABSTRACT FROM AUTHOR]

To address the disadvantage of poor degradation effect of Fe2+/peroxydisulfate (PDS) system, a co-catalyst was introduced in this study to construct a molybdenum (Mo)/Fe2+/PDS system for the degradation of Acid Orange 7 (AO7), and the degradation rate could reach 95.67%. The effects of different parameters (initial pH, Fe2+ concentration, etc.) on the degradation effect of AO7 in this system were investigated, and the optimal degradation conditions were obtained by combining cost analysis. Cycling experiments showed that Mo had good stability. The co-catalytic mechanism of Mo powder was determined using X-Ray Diffraction, Scanning Electron Microscope, and X-ray Photoelectron Spectroscopy. The effects of different inorganic anions on AO7 were discussed: Cl− and NO3− had little effect on degradation, while SO42− and HCO3− both inhibited the removal of AO7 from the system to different degrees, with HCO3− showing a greater inhibition than SO42−. The main active radicals were identified as sulfate radical (SO4·−) and hydroxyl radical (·OH). In addition, intermediates were identified, and the attack sites were determined by combining the highest occupied molecular orbital/lowest unoccupied molecular orbital energy levels and the Fukui index to hypothesize the degradation pathways. Toxicity indicators such as the mutagenicity of AO7 and intermediates were evaluated, and the overall trend of toxicity was decreasing. This study is expected to provide an efficient treatment process for dye wastewater. [ABSTRACT FROM AUTHOR]

Molybdenum‐based efficient and broadly applicable catalytic system is presented for the dehydrogenative coupling of γ‐/β‐amino alcohols with ketones. In particular, complex Mo(CO)6 in combination with Xantphos and t‐BuOK as base provides direct synthesis of structurally diverse quinoline, pyridine, and pyrrole compounds (total 55 examples) with isolated yields up to 92%. Low catalyst loading, cost‐effective, and high catalytic activities with high tolerance to stand with diverse functional groups are additional features of these molybdenum catalysts exhibiting high efficacy to replace the precious metal catalysts such as ruthenium and iridium. Furthermore, the DFT and experimental studies were explored for the reaction mechanism which can assist in broadening the scope of the molybdenum catalysts for different transformation reactions. [ABSTRACT FROM AUTHOR]

Molybdenum tailings are accumulated in large quantities, occupying the land and polluting the environment. Therefore, the resource utilization of molybdenum tailings is imperative. In this paper, the influence of molybdenum tailings powder (MTs) as admixture on hydration characteristics, including hydration heat, hydration products, phase composition, and mechanical properties evolution of cement paste were investigated. Results showed that the early hydration of cement paste can be promoted when the content of MTs is not more than 15%. The compressive strength of cement paste with 15% MTs at 3, 28, and 120 days was 89.37%, 96.14%, and 91.68% of that of the portland cement (PC) group, respectively. When the content of MTs does not exceed 15%, the second exothermic peak of hydration heat of cement paste appears ahead of time and the peak value increases. With the increase of MTs content, the cumulative heat release of 72 h gradually decreased. The addition of MTs does not produce new hydration products, but introduces the mineral phase of MTs itself, and leads to the early transformation of ettringite (AFt) into monosulfoaluminate (AFm) in paste. There is still a close linear relationship between the compressive strength and cumulative heat release and chemically bound water content after addition of MTs into cement paste. It was also discovered that the pozzolanic activity of MTs in cement paste mainly occurred from 3 to 28 days. After 28 days, the particle-filling effect of MTs was dominant mainly. The research results are expected to provide basic research for the resource utilization of MTs. [ABSTRACT FROM AUTHOR]

The cathode in lithium-selenium (Li-Se) batteries has garnered extensive attention owing to its superior specific capacity and enhanced conductivity compared to sulfur. Nonetheless, the adoption and advancement of Li-Se batteries face significant challenges due to selenium's low reactivity, substantial volume fluctuations, and the shuttle effect associated with polyselenides. Single-atom catalysts (SACs) are under the spotlight for their outstanding catalytic efficiency and optimal atomic utilization. To address the challenges of selenium's low chemical activity and volume expansion in Li-Se batteries, through electrospun, we have developed a lotus root-inspired carbon nanofiber (CNF) material, featured internal multi-channels and anchored with molybdenum (Mo) single atoms (Mo@CNFs). Mo single atoms significantly enhance the conversion kinetics of selenium (Se), facilitating rapid formation of Li2Se. The internally structured multi-channel CNF serves as an effective host matrix for Se, mitigating its volume expansion during the electrochemical process. The resulting cathode, Se/Mo@CNF composite, exhibits a high discharge specific capacity, superior rate performance, and impressive cycle stability in Li-Se batteries. After 500 cycles at a current density of 1 C, it maintains a capacity retention rate of 82% and nearly 100% coulombic efficiency (CE). This research offers a new avenue for the application of single-atom materials in enhancing advanced Li-Se battery performance. [ABSTRACT FROM AUTHOR]

Low-cost, small-sized, and easy integrated high-performance photodetectors for photonics are still the bottleneck of photonic integrated circuits applications and have attracted increasing attention. The tunable narrow bandgap of two-dimensional (2D) layered molybdenum ditelluride (MoTe2) from ∼0.83 to ∼1.1 eV makes it one of the ideal candidates for near-infrared (NIR) photodetectors. Herein, we demonstrate an excellent waveguide-integrated NIR photodetector by transferring mechanically exfoliated 2D MoTe2 onto a silicon nitride (Si3N4) waveguide. The photoconductive photodetector exhibits excellent responsivity (R), detectivity (D *), and external quantum efficiency at 1550 nm and 50 mV, which are 41.9 A W−1, 16.2 × 1010 Jones, and 3360%, respectively. These optoelectronic performances are 10.2 times higher than those of the free-space device, revealing that the photoresponse of photodetectors can be enhanced due to the presence of waveguide. Moreover, the photodetector also exhibits competitive performances over a broad wavelength range from 800 to 1000 nm with a high R of 15.4 A W−1 and a large D * of 59.6 × 109 Jones. Overall, these results provide an alternative and prospective strategy for high-performance on-chip broadband NIR photodetectors. [ABSTRACT FROM AUTHOR]

A family of molybdenum complexes with a general formula of [MoO2L]2 have been synthesized and fully characterized, where L is a tridentate ONO Schiff base ligand featuring a Cl substituent in different positions on the aromatic ring of salicylidene‐2‐aminophenolato backbone. The solvent molecule stabilized the monomeric structure of [MoO2LD] (D = DMF or DMSO) allowing single‐crystal X‐ray diffraction of the three new complexes. The dimeric complexes are utilized to catalyze the reaction of aldehydes/ketones with dimedone, leading to 1,8‐dioxo‐octahydro‐xanthene derivatives in N,N‐dimethylformamide. We found that their catalytic activity is enhanced by the electron‐withdrawing group of the Cl substituent on the ONO ligand. In addition, the position of the Cl substituent can also positively influence the catalysis performance: (ortho (L1) > para (L3) > meta (L2) ≈ meta (L4)). The high efficiency of the catalysts promises high yields and selectivity with a low catalyst loading and allows a wide substrate scope of aldehydes/ketones for the reaction. In addition, the method employs recrystallization for purifying products and can be easily scaled up to gram levels, indicating a strong potential for industrial utilization. [ABSTRACT FROM AUTHOR]

Herein, a novel bimetallic nickel molybdenum nitride (Ni3Mo3N) catalyst is reported for the first time for the hydrogenation of dimethyl oxalate (DMO) to ethanol (EtOH). Remarkably, the Ni3Mo3N-600 catalyst realizes a remarkable 97.5% EtOH yield at a low pressure of 0.5 MPa and a low H2/DMO molar ratio of 10. Moreover, it exhibits exceptional catalytic stability for at least 300 h, marking the first instance of achieving such high EtOH yield under mild reaction conditions. The present study investigates the impact of different reduction temperatures on the catalyst, and various characterization analyses reveal the formation of Ni3Mo3N. The electron-rich structure of the Ni3Mo3N-600 catalyst facilitates the activation of C＝O and enhances the adsorption and dissociation of H2. Specifically, the low-valence Mo promotes the activation of carbonyl oxygen, while Ni0 facilitates the adsorption and dissociation of H2, considerably enhancing the deep hydrogenation ability of the Ni3Mo3N-600 catalyst. Furthermore, the well-defined crystallinity of the Ni3Mo3N-600 catalyst coupled with Lewis acid sites that promote C＝O adsorption and activation, Brønsted acid sites that facilitate C–O adsorption and activation, and hydrogenation sites collectively contribute to the efficient conversion of DMO to EtOH. This study presents new insights into designing high-performance catalysts for the hydrogenation of DMO toward EtOH. [ABSTRACT FROM AUTHOR]

We have demonstrated a green aqueous synthesis of rod-shaped MoO3 material, [MoVI3O9{K(H2O)4}(CH3COO)]·H2O (2) intercalating potassium–aqua-complex acetate into its lamellar space, simply by ion-exchange of Co(II)–aqua-complex in compound [MoVI4O12(CH3COO)2{CoII(H2O)6}]·2H2O (1) by {K(H2O)4}+ in an aqueous solution of 1 and KCl. Compound 2 acts as a potential storage system of alkali metal ions. [ABSTRACT FROM AUTHOR]

Contamination of soils by Molybdenum (Mo) has raised increasing concern worldwide. Both fulvic acid (FA) and humic acid (HA) possess numerous positive properties, such as large specific surface areas and microporous structure that facilitates the immobilization of the heavy metal in soils. Despite these characteristics, there have been few studies on the microbiology effects of FA and HA. Therefore, this study aimed to assess the Mo immobilization effects of FA and HA, as well as the associated changes in microbial community in Mo-contaminated soils (with application rates of 0%, 0.5% and 1.0%). The result of the incubation demonstrated a decrease in soil pH (from 8.23 ~ 8.94 to 8.05 ~ 8.77). Importantly, both FA and HA reduced the exchangeable fraction and reducible fraction of Mo in the soil, thereby transforming Mo into a more stable form. Furthermore, the application of FA and HA led to an increase in the relative abundance of Actinobacteriota and Firmicutes, resulting in alterations to the microbial community structure. However, it is worth noting that due to the differing structures and properties of FA and HA, these outcomes were not entirely consistent. In summary, the aging of FA and HA in soil enhanced their capacity to immobilization Mo as a soil amendment. This suggests that they have the potential to serve as effective amendments for the remediation of Mo-contaminated soils. [ABSTRACT FROM AUTHOR]

Mo is a key solid solution strengthening element that improves the mechanical properties of Ni-based superalloys, but the partitioning behavior of Mo remains controversial. Herein, we uncover the effect of Mo addition on the precipitation kinetics of the γ′ phase in Ni–(17−x) Al–x Mo at.% (x = 2, 3, 4, and 5) alloys by directly coupling accurate thermodynamic and kinetic descriptions with a phase-field model. Our simulations show that the addition of Mo would decrease the γ′ coarsening rate due to the decrease in the diffusion rate and the γ/γ′ lattice misfit. Besides, the partitioning behavior of Mo is reversed from the γ′ phase ( K Mo γ ′ / γ > 1 ) into the γ matrix ( K Mo γ ′ / γ < 1 ) with increasing Mo concentration, which is attributed to the solubility limit of Mo in the γ′ phase as well as a decrease in the γ/γ′ lattice misfit. Meanwhile, Al and Mo preferentially occupy the Al sublattice site of the γ′–Ni3Al and form the Ni3(Al, Mo) phase in Ni–Al–Mo ternary model alloys. Furthermore, the solid solution strengthening effect increases with increasing Mo concentration because of an increase in the Mo concentration in the γ matrix. Our results provide valuable insights into understanding the effect of Mo addition to Ni-based superalloys on the coarsening kinetics of γ′ phase and elemental partitioning behavior. [ABSTRACT FROM AUTHOR]

[Display omitted] The extensive examination of hexagonal molybdenum carbide (β-Mo 2 C) as a non-noble cocatalyst in the realm of photocatalytic H 2 evolution is predominantly motivated by its exceptional capacity to adsorb H+ ions akin to Pt and its advantageous conductivity characteristics. However, the H 2 evolution rate of photocatalysts modified with β-Mo 2 C is limited as a result of their comparatively low ability to release H through desorption. Therefore, a facile method was employed to synthesize carbon intercalated dual phase molybdenum carbide (MC@C) quantum dots (ca. 3.13 nm) containing both α-MoC and β-Mo 2 C decorated on g-C 3 N 4 (gCN). The synthesis process involved a simple and efficient combination of sonication-assisted self-assembly and calcination techniques. 3-MC@C/gCN exhibited the highest efficiency in generating H 2 , with a rate of 4078 µmol g−1h−1 under 4 h simulated sunlight irradiation, which is 13 times higher than pristine gCN. Furthermore, from the cycle test, 3-MC@C/gCN showcased exceptional photochemical stability of 65 h, as it maintained a H 2 evolution rate of 40 mmol g−1h−1. The heightened level of activity observed in the 3-MC@C/gCN system can be ascribed to the synergistic effects of MoC-Mo 2 C that arise due to the existence of a carbon layer. The presence of a carbon layer enhanced the transmission of photoinduced electrons, while the MoC-Mo 2 C@C composite served as active sites, thereby facilitating the H 2 production reaction of gCN. The present study introduces a potentially paradigm-shifting concept pertaining to the exploration of novel Mo-based cocatalysts with the aim of augmenting the efficacy of photocatalytic H 2 production. [ABSTRACT FROM AUTHOR]

Methane release from marine sediments strongly influences the local seafloor environment and ecosystems, and may impact Earth's climate system. Recent studies revealed anomalous molybdenum (Mo) enrichment in seep sediments, which was linked to methane release events. Marine seep sediments are a potential sink of Mo for the global ocean, while the mechanisms leading to local Mo enrichment are not fully understood. The sediments from a gas hydrate-bearing area of the South China Sea analyzed herein reveal authigenic Mo (Mo auth) contents ranging from 0 and 31.4 µg/g and δ98Mo auth values ranging from 0.18 ‰ to 3.31 ‰. The range of δ98Mo auth values of seep sediments is therefore similar to values of modern iron-rich sediments with low concentrations of dissolved porewater hydrogen sulfide and sediments deposited under weakly euxinic sediments. Among the obtained South China Sea data, the more positive δ98Mo auth values (>ca. 1.5 ‰) are interpreted to reflect diffusion of seawater Mo into the sediment at moderate seepage rates and Mo isotope fractionation during the formation of thiomolybdates in the sulfidic seep environment. The lower δ98Mo auth values (

Spheres comprising 10 wt.% Mo2C/γ-Al2O3, synthesized through the sucrose route, exhibited unprecedented catalytic activity for olefin hydrogenation within an industrial naphtha feedstock that contained 23 wt.% olefins, as determined by supercritical fluid chromatography (SFC). The catalyst demonstrated resilience to sulfur, exhibiting no discernible deactivation signs over a tested 96 h operational period. The resultant hydrogenated naphtha from the catalytic process contained only 2.5 wt.% olefins when the reaction was conducted at 280 °C and 3.44 × 106 Pa H2, subsequently blended with Athabasca bitumen to meet pipeline specifications for oil transportation. Additionally, the carbide catalyst spheres effectively hydrogenated olefins under steam conditions without experiencing any notable hydrogenation in the aromatics. We propose the supported carbide catalyst as a viable alternative to noble metals, serving as a selective agent for olefin elimination from light petroleum distillates in the presence of steam and sulfur, mitigating the formation of gums and deposits during the transportation of diluted bitumen (dilbit) through pipelines. [ABSTRACT FROM AUTHOR]

This density functional theory (DFT) study explores the efficacy of cooperative catalytic systems in enabling the ionic hydrogenation of N2 with H2, leading to NH3 formation. A set of N-heterocyclic carbene-based pincer tungsten/molybdenum metal complexes of the form [(PCP)M1(H)2] (M1 = W/Mo) were chosen to bind N2 at the respective metal centres. Simultaneously, cationic rhodium/iridium complexes of type [Cp*M2{2-(2-pyridyl)phenyl}(CH3CN)]+ (Cp* = C5(CH3)5 and M2 = Rh/Ir), are employed as cooperative coordination partners for heterolytic H2 splitting. The stepwise transfer of protons and hydrides to the bound N2 and intermediate NxHy units results in the formation of NH3. Interestingly, the calculated results reveal an encouraging low range of energy spans ranging from ∼30 to 42 kcal mol−1 depending on different combinations of ligands and metal complexes. The optimal combination of pincer ligand and metal center allowed for an energy span of unprecedented 29.7 kcal mol−1 demonstrating significant potential for molecular catalysts for the N2/H2 reaction system. While exploring obvious potential off-cycle reactions leading to catalyst deactivation, the computed results indicate that no increase in energy span would need to be expected. [ABSTRACT FROM AUTHOR]

The assembly of molybdenum polyoxometalates (POMs) has afforded large discrete nanoclusters with varied degrees of reduction such as the ~20 % reduced molybdenum blues. While many heterometals have been incorporated into these clusters to afford new properties, uranium has yet to be reported. Here we report the first uranium containing molybdenum blue clusters and the unique properties exhibited by this incorporation. The uranyl ion (UO22+) directs formation of Mo72U8, a square POM comprised of two faces connected by eight edge‐sharing molybdenum dimers. Mo72U8, a chiral cluster, crystallizes as a racemic mixture and, in the solid state, has a 'negative' charge localized on one face of the cluster opposite the 'positively' charged face of another cluster. Using U(IV) as both heterometal and molybdenum reductant afforded crystals of Mo97U10, a wheel cluster with a heptamolybdate cap on one face. Mo97U10 dissociates in solution, losing the heptamolybdate, to form Mo90U10. Using more solvent during synthesis afforded crystals of Mo90U10S4 which, instead of heptamolybdate, contains four sulfate ions. Crystals of Mo90U10S4 undergo a dehydration induced phase change where clusters form a sheet through oxide bridges. Half of the bridges are cation‐cation interactions between the uranyl oxygen atom and molybdenum, the first reported of this kind. [ABSTRACT FROM AUTHOR]

Direct methanol fuel cells (DMFC) are a promising new energy source. However, the lack of high-performance and low-cost methanol oxidation electrocatalysts hinders their commercial application. Firstly, we successfully prepared NENU-5-derived molybdenum carbide material (Cu-MoC) via a co-precipitation and high-temperature carbonization method using a material composed of a copper-based metal–organic skeleton and a molybdenum-based carbide as the main body. Secondly, PtCu nano-alloy catalysts (Pt/Cu-MoC) were prepared using a unique, spontaneous single replacement reaction after metal–organic skeleton (MOF) carbonization. Through the synergistic effect between Pt and Cu and the strong interaction between Mo2C and PtCu, the electronic structure of the Pt is modified, the energy of the d-band center is reduced, electron exchange is accelerated, and catalytic activity is enhanced. Compared with a commercial Pt/C catalyst in alkaline environments, the Pt0.10/Cu-MoC catalyst has a better MOR catalytic activity (563.25 mA mgPt−1), which is 1.5 times higher than that of commercial Pt/C (376.67 mA mgPt−1). The Pt0.10/Cu-MoC catalyst has an onset potential for CO oxidation that is 16 mV lower than that of commercial Pt/C, indicating better resistance to CO poisoning. Exploring carbon materials derived from MOFs with excellent junction support and using them as carriers to prepare Pt-based catalysts is a practical and feasible approach. It provides a way to develop new Pt-based catalysts that perform efficient MOR. [ABSTRACT FROM AUTHOR]

The mechanism of formation of self-organized patterns on Si substrate with simultaneous co-sputtering of molybdenum by low-energy ion beam sputtering has been investigated. The experiment was carried out using a 1 keV Ar ion beam at normal incidence with different ion fluence (1016–1018 ions.cm−2). To explore the mechanism of pattern evolution in the presence of impurities (Mo atom), the morphological details of the samples with different ion fluence, as well as with respect to the distance from the Mo target were examined by atomic force microscopy (AFM). The evolution of the surface pattern depends on the ion fluence and a pattern transition from ripple to ripple + dot, and dot was observed with distance from the Mo target. RBS, XPS and XRR measurements were also carried out to understand the mechanism of the surface evolution process. [ABSTRACT FROM AUTHOR]

Molybdenum Trioxide nanoparticle (MoO3-NPs) was introduced to Cellulose acetate (CA) biopolymer with different concentration using casting process by dispersed MoO3-NPs [0.0, 0.25, 0.5 and 1.0 wt%]. Molecular structure of samples has been studied using XRD and UV–Vis. the data shown by X-ray results indicated the amorphous nature of the pure polymer. Some peaks are appeared as a result of the addition of MoO3-NPs which indicate that samples were partially crystallized. The crystallite size of nano-metal oxide was calculated for blended samples by Size–Strain Plot method which was found to increase with increasing the concentration of MoO3. UV–Vis results indicate that there exist two indirect energy band gaps; Onset band gap which observed to decreases from 1.3 eV for pure polymer to 0.78 eV for polymer blended with 1.0 wt% MoO3-NPs and HOMO–LOMO band gap which observed to decrease from 3.23 eV for pure polymer to 2.89 eV for polymer blended with 1.0 wt% MoO3-NPs. This indicate that the addition of nano-metal oxide improve the optical conduction of CA. Urbach energy was observed to increase with increasing MoO3-NPs from 0.27 eV for pure CA to 0.32 eV for 1.0 wt% MoO3-NPs concentration which may be occurred due to the creation localized states at the band gap as a result of the addition of MoO3-Nps. [ABSTRACT FROM AUTHOR]

The effects of solution treatment and annealing temperature on the microstructure and mechanical properties of a new TWIP steel that was alloyed from aluminum (Al), silicon (Si), vanadium (V), and molybdenum (Mo) elements were investigated by a variety of techniques such as microstructural characterization and room tensile testing. The austenite grain size grew slowly with the increase in annealing temperature. The relatively weak effect of the solution treatment and annealing temperature on the austenite grain size was attributed to the precipitation of MC and M2C, which hindered the growth of the austenite grain. The plasticity of the TWIP steel in cold rolling and annealing after solution treatment was obviously higher than that in cold rolling and annealing without solution treatment. This was because the large-size precipitates redissolved in the matrix after solution treatment, which were not retained in the subsequently annealed structure. Through cold rolling and annealing at 800 °C after solution treatment, the prepared steel exhibited excellent strength and plasticity simultaneously, with a yield strength of 877 MPa, a tensile strength of 1457 MPa, and an elongation of 46.1%. The strength improvement of the designed TWIP steel was mainly attributed to the grain refinement and precipitation strengthening. [ABSTRACT FROM AUTHOR]

This study aimed to synthesize molybdenum complexes coordinated with an aroyl hydrazone-type ligand (H2L), which was generated through the condensation of 2-hydroxy-5-nitrobenzaldehyde with benzhydrazide. The synthesis yielded two types of mononuclear complexes, specifically [MoO2(L)(MeOH)] and [MoO2(L)(H2O)], as well as a bipyridine-bridged dinuclear complex, [(MoO2(L))2(4,4'-bpy)]. Those entities were thoroughly characterized using a suite of analytical techniques, including attenuated total reflectance infrared spectroscopy (IR-ATR), elemental analysis (EA), thermogravimetric analysis (TGA), and single-crystal X-ray diffraction (SCXRD). Additionally, solid-state impedance spectroscopy (SS-IS) was employed to investigate the electrical properties of these complexes. The mononuclear complexes were tested as catalysts in the epoxidation of cyclooctene and the oxidation of linalool. Among these, the water-coordinated mononuclear complex, [MoO2(L)(H2O)], demonstrated superior electrical and catalytic properties. A novel contribution of this research lies in establishing a correlation between the electrical properties, structural features, and the catalytic efficiency of the complexes, marking this work as one of the pioneering studies in this area for molybdenum coordination complexes, to the best of our knowledge. [ABSTRACT FROM AUTHOR]

The corrosion behavior of electrodeposited nickel-based coatings with W, Mo, and TiOx as potential catalytic material for hydrogen evolution reaction (HER) in highly aggressive media, 0.5 M H2SO4 and 6 M KOH, is presented. A wide range of electrochemical and spectroscopic methods have been used, such as linear sweep voltammetry, open-circuit potential (OCP), electrochemical impedance spectroscopy (EIS), X-ray diffraction (XRD), X-ray fluorescence spectroscopy (XRF), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and energy-dispersive spectroscopy (EDS) to characterize the coatings before and after a residence time of 336 h in the model corrosion environment. The NiW alloy and the NiWTiOx composite coating demonstrate the best corrosion resistance in an acidic environment due to the stable tungstate phase formation (H0.33O3W and H2O4W) on the surface. In alkaline environments, all the systems studied show enviable resistance, but the alloys containing molybdenum stand out. [ABSTRACT FROM AUTHOR]

Oxidative coupling of methane (OCM) is a promising process of direct transformation of CH4 to ethylene instead of a complicated two-step process in terms of first forming syngas through reforming or partial oxidation and then producing ethylene with Fischer–Tropsch synthesis (FTS). Na2WO4 has been one of the most studied catalysts of OCM. Here we investigated how the introduced transition metal elements Co, Mn, or Mo to Na2WO4 could influence the catalytic performance of OCM on the supported Na2WO4. It is found that Co, Mn and Mo can obviously promote catalytic activity of transforming CH4 and selectivity for producing ethylene and ethane in OCM performed on Na2WO4 supported on microporous silicate-1 (S-1). A similar promotion of Co, Mn and Mo to the catalytic activity and selectivity in OCM performed on Na2WO4 was found when the Na2WO4 was supported on Matériaux de l′Institut Lavoisier-53(Al) [MIL-53(Al)]. X-ray absorption near edge structure (XANES) and extended X-ray absorption fine structure (EXAFS) spectroscopy studies of these catalysts with added transition metal Co, Mn or Mo show that these metals diffused into the lattice of Na2WO4, further suggesting that the promotional effect likely arises from modification of the active phase of the supported Na2WO4 during OCM. [ABSTRACT FROM AUTHOR]

There are very few known examples of supramolecular compounds comprising molybdenum species hosted inside the portals/cavities of cucurbit[n]urils (CBn). In this work, CB7 and CB8 macrocycles have been studied as hosts for the carbonyl complex [CpMo(CO)3Me] (1) (Cp = η5‐C5H5). Compounds were isolated in the solid state and characterized as genuine 1:1 inclusion complexes (1@CBn) by elemental and thermogravimetric analyses, powder X‐ray diffraction, scanning electron microscopy, 13C{1H} cross‐polarization magic‐angle spinning NMR, FT‐IR, Raman, and diffuse reflectance UV–Vis spectroscopies. The host–guest structures can act as supramolecular precatalysts for olefin epoxidation. Based on the model reaction of cis‐cyclooctene with hydroperoxide oxidants (tert‐butylhydroperoxide or hydrogen peroxide), the structural features of 1@CBn as well as the operating conditions influence the catalytic process. The metal species in 1@CBn undergo oxidative decarbonylation in situ, giving oxidized metal species that are catalytically active for olefin epoxidation. The type of oxidant and solvent influences the catalytic activity and stability. 1@CB8 was more stable than 1@CB7 with regard to catalyst recycling and reuse. Based on the substrate scope investigation, for relatively large olefins, such as the fatty acid methyl ester methyl oleate, the size of the macrocyclic host may be a determining factor for catalytic activity. [ABSTRACT FROM AUTHOR]

An inter-laboratory comparison involving three participants (PTB, CAE, TU Graz) was conducted on spectral emissivity measurements using experimental setups covering a temperature range from 1250 K to 4000 K and a spectral range between 0.6 µm and 20 µm. The main objective here was to carry out a European-level assessment of the coherency of spectral emissivity measurements at high temperatures. Three refractory materials (molybdenum, tungsten and isotropic graphite) were selected for this comparison. Samples were machined from the same batch of materials and then sandblasted and thermally annealed (PTB, CAE) to achieve uniform and stable surface properties and reduce potential scattering of results between participants. The spectral emissivity of the three materials was then measured by each of the three participants up to the maximum temperature attainable by the devices used. In the overlapping wavelength range from 600 nm to 1100 nm, all measurement methods were in good agreement with regards to their respective uncertainties. [ABSTRACT FROM AUTHOR]

There is intensive research by the community to improve materials for renewable energy applications such as hydrogen production, photovoltaics and light-emitting diodes. Titanium dioxide (TiO2) is an important material where we can improve its fundamental properties, through doping aiming to form more efficient devices. Here, we use electronic structure calculations based on density function theory (DFT) to explore the effect of dopants, such as boron (B), germanium (Ge), molybdenum (Mo), and tungsten (W), on the structural and electronic properties of TiO2. We investigated both the interstitial and the oxygen substitutional positions, and for the minimized energy optimized structures, we used hybrid DFT calculations to predict the electronic properties through the density of states, which proved costly but not as much to outweigh their advantage in accuracy. For most cases considered, the dopants reduce the theoretical bandgap of TiO2, while gap states form. The variation of the bandgap ranges from a very small increase of 0.04 eV to a significant decrease of 0.8 eV, while the exact "position" of new gap states differs for each type of dopant and for its "spot" in the crystalline structure. It is proposed that these states and the change of the bandgap contribute to the significant changes in the optical and electronic properties of TiO2 and can be beneficial to the photovoltaic and photocatalytic applications of TiO2 and its implementation for hydrogen production. [ABSTRACT FROM AUTHOR]

The main challenge for sodium storage is to find suitable host materials to accommodate larger-sized Na+ and conquer sluggish chemical kinetics. Herein, by adjusting the heat treatment environment, a novel few-layered molybdenum oxide selenide encapsulated in a three-dimensional (3D) N-doped carbon skeleton (MoO3–MoSe2–NC) is rationally constructed to improve the rate performances and cycle life for sodium-ion batteries (SIBs). A small quantity of MoO3 is generated on the edge of MoSe2via in situ local phase transformation by treatment temperature in the air, which effectively regulates the electronic structure, enhances the intrinsic conductivity, and provides more active sites of MoSe2 species. The layered NC acts as a nanoreactor to encapsulate MoO3–MoSe2, which not only effectively improves the conductivity of MoO3–MoSe2, shortens the diffusion pathway of Na+, but also alleviates the volumetric expansion effect of MoO3–MoSe2, playing a key role in providing structural stability for the electrode. Utilizing the phase and interface engineering, the MoO3–MoSe2–NC anode delivers a high specific capacity of 551 mA h g−1 at 0.1 A g−1 upon 150 cycles for SIBs, and a reversible capacity of 368 mA h g−1 is maintained even under 1 A g−1 after 600 cycles. By pairing with commercial Na3V2(PO4)3, this MoO3–MoSe2–NC also exhibits excellent performances in full cells. This study develops a universal interface manipulation strategy for the synthesis of anode materials to boost fast sodium storage kinetics. [ABSTRACT FROM AUTHOR]

We study the influence of mechanical deformations on the Zeeman and Rashba effects in transition metal dichalcogenide nanotubes and their Janus variants from first principles. In particular, we perform symmetry-adapted density functional theory simulations with spin–orbit coupling to determine the variation in the electronic band structure splittings with axial and torsional deformations. We find significant effects in molybdenum and tungsten nanotubes, for which the Zeeman splitting decreases with increase in strain, going to zero for large enough tensile/shear strains, while the Rashba splitting coefficient increases linearly with shear strain, while being zero for all tensile strains, a consequence of the inversion symmetry remaining unbroken. In addition, the Zeeman splitting is relatively unaffected by nanotube diameter, whereas the Rashba coefficient decreases with increase in diameter. Overall, mechanical deformations represent a powerful tool for spintronics in nanotubes. [ABSTRACT FROM AUTHOR]

Silanones (O＝SiR2), a heavier congener of ketones (R2C＝O), are highly reactive species that are readily converted to oligomeric siloxane (O–SiR2)n. Coordination of silanones to the transition-metal fragments to afford silanone-coordinated complexes is a reliable silanone stabilization method. Recently, our group reported the synthesis, structures, and reactivity of dimesityl-substituted silanone complexes Cp*(OC)2M{O＝SiMes2(L)}(SiMe3) (M = W, Mo, L: Lewis base, Cp*: η5-C5Me5, Mes: 2,4,6-Me3C6H2). Herein, to investigate the effect of substituents on the silicon atom during the formation of a silanone complex, we demonstrated the use of Mes and smaller Me groups. As a result, the formation of Mes(Me)-substituted silanone molybdenum complex Cp*(OC)2Mo{O＝SiMes(Me)(py)}(SiMe3) (5b, py: pyridine) was suggested, the silanone tungsten complex Cp*(OC)2W{O＝SiMes(Me)(DMAP)}(SiMe3) (4a, DMAP: 4-(dimethylamino)pyridine) was obtained, and a dimethyl-substituted disiloxanyloxy(dioxo) complex Cp*(O)2W(OSiMe2OSiMe3) (9) was formed. The reaction of 4a with PMe3 proceeded via the elimination of DMAP and migration of the SiMe3 group to the oxygen atom of the silanone ligand to afford Cp*(OC)2W(SiMes(Me)OSiMe3)(PMe3) (11a). The Mo complex Cp*(OC)2Mo(SiMes(Me)OSiMe3)(PMe3) (11b) was produced by the reaction of Cp*(OC)2Mo{＝SiMes(Me)}(SiMe3) (7b) with pyridine-N-oxide in the presence of PMe3. [ABSTRACT FROM AUTHOR]