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Porous mullite ceramics were synthesized via ceramic processing using a local industrial kaolin, alumina, and with AlF3 and MoO3 precursor additives to catalyze the formation of pores and acicular mullite grains. The textural properties, crystalline phases, microstructures, and mechanical properties of the obtained samples were comprehensively analyzed and compared with a reference mullite formulated without additives. The obtained ceramics have a well‐defined porous microstructure, with a porosity of about 50%, and a pore size distribution in the 0.1–2 µm range. Ceramics that involve the addition of MoO3 present well‐defined acicular mullite grains, with slightly higher porosity, larger pores, and better mechanical resistance compared to those processed using AlF3.To correlate the ceramic porosity with its mechanical properties, a simple model of spherical pores was proposed to assess the flexural strength of the dense ceramic. It was found that the inclusion of additives promoting needle‐like microstructures increases the mechanical resistance up to four times the value determined for the ceramic without additives (flexural strength up to 390 MPa for zero‐porosity extrapolation). These results, together with the refractoriness of mullite, allow inferring the potential applications of the developed materials as structural ceramics with relatively low density and for filtering applications. [ABSTRACT FROM AUTHOR]

Bioresorbable electrochemical sensors remain mostly unexplored despite their ability to provide continuous in situ measurements of critical biomarkers. The primary challenge arises from the direct exposure of the electrodes' thin metal films to biofluids, which poses difficulties in ensuring both proper operational lifetimes and sensing performance. Molybdenum (Mo) presents itself as a promising biometal due to its uniquely gradual dissolution in biofluids, facilitated by the formation of a slower‐dissolving MoOx surface layer. Consequently, carefully engineered MoOx films can endow transient electrochemical sensors with unparalleled stability during extended operational lifetimes. Herein an unprecedented sensor architecture achieved via the unique pairing of sputtered Mo and MoOx thin films, probed as a pH and dissolved oxygen sensor is reported. Compared to a bare Mo electrode, a bilayer Mo+MoOx electrode subjected to post‐deposition annealing (400 °C, 60 min, N2 environment) displayed a largely improved stability (>24 h) in solution and demonstrated predictable functionality during ongoing film dissolution at 37 °C. Collectively, this work establishes a pioneering strategy for the fabrication of reliable and clinically relevant implantable electrochemical sensors. [ABSTRACT FROM AUTHOR]

The reduction of nitrogen oxides (NOx), critical pollutants from stationary to mobile sources, mainly relies on the selective catalytic reduction (NH3-SCR) method, employing ammonia to reduce NOx into nitrogen and water. However, conventional catalysts, while effective, pose both environmental and operational challenges. This study investigates ceria-zirconia-supported molybdenum-based catalysts, exploring the effects of zirconium doping and different catalyst synthesis techniques, i.e., co-precipitation and impregnation. The catalytic performance of the differently prepared samples was significantly influenced by the molybdenum incorporation method and the zirconium content within the ceria-zirconia support. Co-precipitation at higher temperatures resulted in catalysts with better structural attributes but slightly lower catalytic activity compared to those prepared via impregnation. Optimal NOx reduction (close to 100%) was observed at a 15 mol% zirconium doping level when using the impregnation method. [ABSTRACT FROM AUTHOR]

In this study, the hydrogen reduction mechanism of MoO3 was analyzed in detail using Ti–Mo core–shell powder manufactured through a milling and reduction process. MoO3 and Ti powders were ball-milled to refine the MoO3 powder and coat it onto the Ti powder to fabricated core-shell structure. Subsequently, the milled powder was heat-treated at 600°C in a hydrogen atmosphere to reduce MoO3 to nano-sized Mo. In addition, the reduction behavior of MoO3 was analyzed by varing the reduction times to 1, 10, 30 min and 1, 3, 5 h. Phase analysis was conducted using X-ray diffraction, and oxidation state analysis was conducted using X-ray photoelectron spectroscopy. Morphology analysis was performed using scanning electron microscopy, and elemental analysis was conducted using electron probe micro-analysis. It was confirmed that Mo9O26 and Mo4O11 intermediate phases were formed sequentially as MoO3 was reduced to MoO2, and Mo9O26 had a plate shape with a thickness of sub-70 nm, and Mo4O11 exhibited a thickness of sub-300 nm. Especially, the Mo2O3 intermediate phase, previously studied only theoretically, was experimentally confirmed for the first time in the reduction process from MoO2 to Mo. Furthermore, the analysis of Mo-oxide intermediate phases was explained by the structural characteristics of the core–shell. The shell of Mo oxide was thick and dense, making it difficult for the vapor phase necessary for CVT reduction to penetrate and diffuse into the shell. As a result, the rapid CVT reduction occurred outside the shell, while relatively slower reduction occurred inside the shell where intermediate phases were observed.

Abstract Bioresorbable electrochemical sensors remain mostly unexplored despite their ability to provide continuous in situ measurements of critical biomarkers. The primary challenge arises from the direct exposure of the electrodes’ thin metal films to biofluids, which poses difficulties in ensuring both proper operational lifetimes and sensing performance. Molybdenum (Mo) presents itself as a promising biometal due to its uniquely gradual dissolution in biofluids, facilitated by the formation of a slower‐dissolving MoOx surface layer. Consequently, carefully engineered MoOx films can endow transient electrochemical sensors with unparalleled stability during extended operational lifetimes. Herein an unprecedented sensor architecture achieved via the unique pairing of sputtered Mo and MoOx thin films, probed as a pH and dissolved oxygen sensor is reported. Compared to a bare Mo electrode, a bilayer Mo+MoOx electrode subjected to post‐deposition annealing (400 °C, 60 min, N2 environment) displayed a largely improved stability (>24 h) in solution and demonstrated predictable functionality during ongoing film dissolution at 37 °C. Collectively, this work establishes a pioneering strategy for the fabrication of reliable and clinically relevant implantable electrochemical sensors.

We developed a high-performance CdSe/ZnS quantum-dot light-emitting diode (QLED) incorporating a hole injection layer (HIL) composed of a solution-processed vanadium oxide (VO) and molybdenum oxide (MoO) mixture. The QLED with a VO:MoO ratio of 1:1 in the HIL demonstrated a current efficiency of 62.0 cd/A, representing a 60% improvement over the QLED utilizing poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) as the HIL. Besides improved performance, the substitution of the highly reactive PEDOT: PSS with chemically stable metal oxides in HIL fabrication is anticipated to enhance device reliability. The highest occupied molecular orbital level of the VO:MoO ratio of 1:1 HIL was higher than that of HILs with other mixing ratios. Additionally, the VO:MoO ratio of 1:1 HIL exhibited higher oxidation number states compared to HILs with other mixing ratios. These characteristics contributed to the superior performance of the QLED with the VO:MoO ratio of 1:1 HIL. Our approach, which employs chemically stable metal oxides as HIL materials for high-performance QLEDs, can advance future QLED technology.

In this work, a new MoO3@Mo2CT x nanocomposite was prepared from two–dimensional (2D) Mo2CT x MXene by in situ oxidization in air, which exhibited wonderful lithium-storage performance as anodes of lithium–ion batteries (LIBs). The precursor Mo2CT x was synthesized from Mo2Ga2C by selective etching of NH4F at 180 °C for 24 h. Thereafter, the Mo2CT x was oxidized in air at 450 °C for 30 min to obtain MoO3@Mo2CT x nanocomposite. In the composite, in situ generated MoO3 nanocrystals pillar the layer structure of Mo2CT x MXene, which increases the interlayer space of Mo2CT x for Li storage and enhances the structure stability of the composite. Mo2CT x 2D sheets provide a conductive substrate for MoO3 nanocrystals to enhance the Li+ accessibility. As anodes of LIBs, the final discharge specific capacity of the MoO3@Mo2CT x composite was 511.1 mAh g–1 at a current density of 500 mA g–1 after 100 cycles, which is about 36.7 times that of pure Mo2CT x MXene (13.9 mAh g–1) and 3.2 times that of pure MoO3 (159.9 mAh g–1). In the composites, both Mo2CT x and MoO3 provide high lithium storage capacity and can enhance the performance of each other. Moreover, this composite can be made by a facile method of in situ oxidation. Therefore, the MoO3@Mo2CT x MXene nanocomposite is a promising anode of LIB with high performance. [ABSTRACT FROM AUTHOR]

[Display omitted] Monkeypox is a zoonotic viral infection caused by the monkeypox virus (MPXV), which belongs to the Poxviridae family of the Orthopoxvirus (OPXV) genus. Monkeypox is transmitted from animals to humans and humans to humans; therefore, the accurate and early detection of MPXV is crucial for reducing mortality. A novel graphene-based material, graphene quantum rods (GQRs) was synthesized and confirmed using high-resolution transmission electron microscopy (HR-TEM) and atomic force microscopy (AFM). In this study, molybdenum oxide was electrodeposited and one-pot electrodeposition of MoO 3 -GQRs composite on carbon fiber paper (CFP) enabled by an antibody (Ab A29)/MoO 3 -GQRs immunoprobe was developed for the early diagnosis of MPXV protein (A29P). Several studies were conducted to analyze the MoO 3 -GQRs composite, and the prepared Ab A29/MoO 3 -GQRs immunoprobe selectively bound to the A29P antigen that was measured using differential pulse voltammetry (DPV) analysis and impedance spectroscopy. The antigen–antibody interaction was analyzed using X-ray photoelectron spectroscopy. DPV analysis showed a wide linear range of detection from 0.5 nM to 1000 nM, a detection limit of 0.52 nM, and a sensitivity of 4.51 µA in PBS. The prepared immunoprobe was used to analyze A29P in serum samples without reducing electrode sensitivity. This system is promising for the clinical analysis of A29P antigen and offers several advantages, including cost-effectiveness, ease of use, accuracy, and high sensitivity. [ABSTRACT FROM AUTHOR]

The adequate optical properties, low cost, and thermal stability of graphitic carbon nitride and molybdenum oxide make them both promising materials for photocatalytic applications. However, they both suffer from strong recombination of their photogenerated charge carriers. Therefore, searching for strategies that enable an efficient charge carrier separation is desirable for improving the photocatalytic performance of both semiconductors. In this work, we have synthesized a g-C3N4/MoO3 heterojunction by a facile solid dispersion approach to the pristine semiconductors that allows a uniform dispersion of the two phases in the heterojunction. The resulting hybrid photocatalyst exhibits light absorption features similar to pristine g-C3N4 and presents an improved separation of the photogenerated charge carriers, likely through a Z-scheme between both semiconductor phases, as inferred by photoelectrochemical measurements. As a result, the g-C3N4/MoO3 heterojunction showed better photocatalytic activity than the individual semiconductors and good cycling stability for the degradation of methylparaben and its reaction intermediates. We drew these conclusions based on total organic carbon (TOC) measurements. [ABSTRACT FROM AUTHOR]

Novel photochromic composites based on biopolymers (polyvinyl alcohol, starch) and Mo4O11 and W18O49 as the fillers were obtained and characterized. To improve the photochromic properties, molybdenum and tungsten oxide sols were treated by an underwater diaphragm discharge to obtain binary structures of the MoOx/WOx and WOx/MoOx (2 < x < 3) types. The formation of such oxides was confirmed by TEM, EDX, XRD analysis, and Raman spectroscopy data. Plasma treatment is increased the color intensity and reversibility. The modified sols were incorporated into polymer matrices. Spectral studies have shown that the color of photo‐colored composites depends on the chemical structure of the polymer matrix. Mechanical tests have shown the possibility of obtaining hardened or plastic composites depending on the concentration and nature of the filler. Highlights: Photochromic polymer composites with W18O49 and Mo4O11 as fillers were obtained.Diaphragm discharge used as a tool for sol modification.WOx/MoOx and MoOx/WOx structures have improved photochromic properties.Color of irradiated polymer composites depends on chemical structure of polymer.Mechanical properties are determined by the polymer filler concentration. [ABSTRACT FROM AUTHOR]

The physicochemical and catalytic (CO2 hydrogenation) characteristics of Mo-containing catalysts were studied. The catalysts containing 8 and 15 wt % Mo oxide were prepared by impregnation of γ‑Al2O3 with ammonium paramolybdate, followed by drying and calcination at 500°C. The introduction of Mo oxide reduced the pore volume of the support and increased the average pore size, indicating that molybdenum oxide was distributed in the support pores. According to the X-ray diffraction analysis, the calcinated catalyst did not contain the crystalline MoO3 phase. According to the Raman spectra, oxygen-containing formations were present on the catalyst surface, with Mo atoms tetrahedrally and octahedrally coordinated to the oxygen atoms. The impregnated MoO3 was partially reduced with hydrogen during linear heating, starting from 320°C. The hydrogenation of CO2 (gas composition, vol %: 30.7 CO2, 68 H2, the rest was N2; 0.5 g sample) was studied under conditions of linear heating to 400°C. The main reaction was the reverse reaction of CO steam reforming. The contribution of methanation to CO2 hydrogenation was small. An increase in the temperature and pressure had a positive effect on CO2 conversion. When the pressure increased from 1 to 5 MPa, the CO content was approximately doubled. In the CO2 hydrogenation, appreciable activity (although significantly lower compared to that of Mo-containing catalysts) was also exhibited by γ-Al2O3, preliminarily heated to 400°C in an H2 flow. The activity of alumina also increased with pressure. [ABSTRACT FROM AUTHOR]

The cutting of difficult to machine materials such as titanium alloys is challenging for the machining industry. In case of the titanium alloy Ti6Al4V, the properties of the material cause high temperatures, mechanical loads as well as high frequency vibrations at the cutting edge, leading to premature tool failure. The use of uncoated carbide tools is very common for machining of Ti based alloys. However, temperature active, self-lubricating physical vapor deposition (PVD) coatings like CrAlMoN showed promising results to reduce friction and wear during turning of Ti6Al4V. In the present study, self-lubricating (Cr34Al41Mo25)N, (Cr29Al36Mo35)N and (Cr25Al31Mo44)N coatings were investigated on cemented carbide tools. These were deposited by a hybrid process combining direct current Magnetron Sputtering and High Power Pulsed Magnetron Sputtering. Coating morphology, thickness, chemical composition, indentation hardness and modulus at ϑ = 20 °C, ϑ = 200 °C, ϑ = 400 °C and ϑ = 600 °C as well as the oxidation behavior were analyzed. Moreover, wear development after cutting tests using a CNC-lathe was investigated. Independent of Mo-content, all coating variants possessed a dense morphology and a smooth surface topography, as well as a coating adhesion class of HF1 to the cemented carbide substrate in Rockwell indentation tests according to DIN 4856. With an increasing amount of Mo, heat treatment temperature and time, more self-lubricating molybdenum oxides such as MoO3 and Mo4O11 were detected by Raman spectroscopy. Therefore, the coating with the highest amount of Mo possessed the highest amount of molybdenum oxides. After cutting tests, molybdenum oxides were also found on the tool flank face by Raman spectroscopy. The level of flank wear land width decreased with increasing amount of Mo. [ABSTRACT FROM AUTHOR]

The physicochemical and catalytic (CO2 hydrogenation) characteristics of Mo-containing catalysts were studied. The catalysts containing 8 and 15 wt % Mo oxide were prepared by impregnation of γ‑Al2O3 with ammonium paramolybdate, followed by drying and calcination at 500°C. The introduction of Mo oxide reduced the pore volume of the support and increased the average pore size, indicating that molybdenum oxide was distributed in the support pores. According to the X-ray diffraction analysis, the calcinated catalyst did not contain the crystalline MoO3 phase. According to the Raman spectra, oxygen-containing formations were present on the catalyst surface, with Mo atoms tetrahedrally and octahedrally coordinated to the oxygen atoms. The impregnated MoO3 was partially reduced with hydrogen during linear heating, starting from 320°C. The hydrogenation of CO2 (gas composition, vol %: 30.7 CO2, 68 H2, the rest was N2; 0.5 g sample) was studied under conditions of linear heating to 400°C. The main reaction was the reverse reaction of CO steam reforming. The contribution of methanation to CO2 hydrogenation was small. An increase in the temperature and pressure had a positive effect on CO2 conversion. When the pressure increased from 1 to 5 MPa, the CO content was approximately doubled. In the CO2 hydrogenation, appreciable activity (although significantly lower compared to that of Mo-containing catalysts) was also exhibited by γ-Al2O3, preliminarily heated to 400°C in an H2 flow. The activity of alumina also increased with pressure. [ABSTRACT FROM AUTHOR]

Electrocatalytic glucose oxidation reaction (GOR) has attracted much attention owing to its crucial role in biofuel cell fabrication. Herein, we load MoO3 nanoparticles on carbon nanotubes (CNTs) and use a discharge process to prepare a noble-metal-free MC-60 catalyst containing MoO3, Mo2C, and a Mo2C–MoO3 interface. In the GOR, MC-60 shows activity as high as 745 µA/(mmol/L cm2), considerably higher than those of the Pt/CNT (270 µA/(mmol/L cm2)) and Au/CNT catalysts (110 µA/(mmol/L cm2)). In the GOR, the response minimum on MC-60 is as low as 8 µmol/L, with a steady-state response time of only 3 s. Moreover, MC-60 has superior stability and anti-interference ability to impurities in the GOR. The better performance of MC-60 in the GOR is attributed to the abundant Mo sites bonding to C and O atoms at the MoO3–Mo2C interface. These Mo sites create active sites for promoting glucose adsorption and oxidation, enhancing MC-60 performance in the GOR. Thus, these results help to fabricate more efficient noble-metal-free catalysts for the fabrication of glucose-based biofuel cells. [ABSTRACT FROM AUTHOR]

Superconducting polycrystalline composites YBa2Cu3O7–x + MoO3 with MoO3 nanofiber content of 1, 5, 10, and 15 wt % have been studied in the work. The temperature and width of transition into the superconducting state of samples with description of possible mechanisms for observable changes have been determined from measurements of electrical resistance. The elastic modulus, yield strength, fracture toughness, and fragility index have been determined from measurements of the Vickers microhardness. Five different models have been used during studies on the physical and mechanical properties of the MoO3-containing bulk HTSC samples to interpret microindentation data and explain the results with consideration of the indentation size effect. [ABSTRACT FROM AUTHOR]

The title compound, (C2H10N2)2[(C10H12N2O8)(MoO3)2]·4H2O, which crystallizes in the monoclinic C2/c space group, was obtained by mixing molybdenum oxide, ethylenediamine and ethylenediaminetetraacetic acid (H4edta) in a 2:4:1 ratio. The complex anion contains two MoO3 units bridged by an edta4− anion. The midpoint of the central C—C bond of the edta4− anion is located on a crystallographic inversion centre. The independent Mo atom is tridentately coordinated by a nitrogen atom and two carboxylate groups of the edta4− ligand, together with the three oxo ligands, producing a distorted octahedral coordination environment. In the three-dimensional supramolecular crystal structure, the dinuclear anions, the organoammonium counter-ions and the solvent water molecules are linked by N—H...Ow, N—H...Oedta and O—H...O hydrogen bonds.

The reduction of nitrogen oxides (NOx), critical pollutants from stationary to mobile sources, mainly relies on the selective catalytic reduction (NH3-SCR) method, employing ammonia to reduce NOx into nitrogen and water. However, conventional catalysts, while effective, pose both environmental and operational challenges. This study investigates ceria-zirconia-supported molybdenum-based catalysts, exploring the effects of zirconium doping and different catalyst synthesis techniques, i.e., co-precipitation and impregnation. The catalytic performance of the differently prepared samples was significantly influenced by the molybdenum incorporation method and the zirconium content within the ceria-zirconia support. Co-precipitation at higher temperatures resulted in catalysts with better structural attributes but slightly lower catalytic activity compared to those prepared via impregnation. Optimal NOx reduction (close to 100%) was observed at a 15 mol% zirconium doping level when using the impregnation method.

Platinum alloys are highly efficient electrocatalysts for the oxygen reduction reaction (ORR) in acidic conditions. However, these alloys are susceptible to metal loss through leaching and degradation, leading to reduced catalyst stability and activity. Recently, it has been shown that doping with oxophilic elements can significantly alleviate these problems, with a prominent example being Mo‐doped Pt alloys. Here, to achieve atomic scale understanding of the exceptional activity and stability of these alloys, we present a detailed density functional theory description of the dopants' structures and impact on electrocatalyst properties. Beginning with the Mo/Pt system, we demonstrate that Mo can be stabilized in the form of low‐dimensional oxyhydroxide moieties on Pt defects. The resulting structures enhance stability and activity via distinct physical processes, with the Mo moieties both directly inhibiting Pt dissolution at defects and indirectly enhancing ORR activity by generation of strain fields on surrounding Pt terraces. We then generalize these analyses to other metal dopant elements, and we demonstrate that similar low‐dimensional oxyhydroxide structures control the electrocatalytic properties through an intricate interplay of the structures' acid stability, intrinsic activity for the ORR, and ability to induce ORR‐promoting strain fields on Pt. [ABSTRACT FROM AUTHOR]

Interfacial engineering is an effective approach for regulating the electronic structure of molybdenum carbides and promoting the hydrogen evolution reaction (HER). However, the development of a facile, cost-effective, and scalable synthesis method is crucial for industrial applications. In this work, we developed a mechanochemical method for the preparation of a composite of MoO 2 /MoC with superior HER electrocatalytic performance in alkaline solutions. The MoO 2 /MoC composite can be easily formed by ball milling for 1 h at ambient conditions, and this process can be scaled up for large-scale industrialization. The composite construction leads to a redistribution of electrons around the interface, optimizing the adsorption energy and enhancing the HER performance beyond that of Pt/C catalysts. This strategy provides a new route for the simple and efficient preparation of high-activity electrocatalysts. [Display omitted] • MoO 2 /MoC composite was obtained via ball milling without external heat input. • MoO 2 /MoC composite enables excellent hydrogen evolution reactions. • MoO 2 /MoC interface tunes electronic structure and favors hydrogen adsorption. • The synthetic route is conducive for industrial manufacturing. [ABSTRACT FROM AUTHOR]

In the present study, a new magnetic acid solid catalyst composed of an agro-industrial waste (rice husk ash-RHA) magnetized with cobalt ferrite (CoFe2O4) and impregnated with MoO3 was synthesized and applied in the methyl transesterification reaction of waste frying oil (WFO) for biodiesel production. The catalyst was synthesized by wet impregnation method and characterized by the following techniques: surface acidity, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy dispersion X-ray spectroscopy (EDS), and vibrating sample magnetometer (VSM). The one variable at time (OVAT) technique was used to optimize the variables of the transesterification reaction in the following ranges: temperature (130.0–170.0 °C), methanol:oil molar ratio (10:1–50:1), catalyst amount (2.0–10.0 wt%), and reaction time (1.0–5.0 h). The results demonstrate that the application of the MoO3/RHA-CoFe2O4 synthesized catalyst resulted in the attainment a biodiesel with ester content of 94.6 % under the optimized reaction conditions: temperature of 160.0 °C, methanol:oil molar ratio of 20:1, catalyst amount of 6.0 wt%, and reaction time of 3.0 h. The biodiesel produced was characterized and presented physicochemical properties in accordance with the limits established by the international standards ASTM D6751 and EN 14214. The kinetic study of the transesterification process revealed that the pseudo-first order model is the most suitable with an activation energy of 27.3 kJ mol−1. In addition, the catalyst showed bifunctional character (catalytic and magnetic), as well as high catalytic stability after ten reaction cycles, maintaining the production of biodiesel with ester content above 70.0 %, indicating its high potential for development and application.

The adequate optical properties, low cost, and thermal stability of graphitic carbon nitride and molybdenum oxide make them both promising materials for photocatalytic applications. However, they both suffer from strong recombination of their photogenerated charge carriers. Therefore, searching for strategies that enable an efficient charge carrier separation is desirable for improving the photocatalytic performance of both semiconductors. In this work, we have synthesized a g-C3N4/MoO3 heterojunction by a facile solid dispersion approach to the pristine semiconductors that allows a uniform dispersion of the two phases in the heterojunction. The resulting hybrid photocatalyst exhibits light absorption features similar to pristine g-C3N4 and presents an improved separation of the photogenerated charge carriers, likely through a Z-scheme between both semiconductor phases, as inferred by photoelectrochemical measurements. As a result, the g-C3N4/MoO3 heterojunction showed better photocatalytic activity than the individual semiconductors and good cycling stability for the degradation of methylparaben and its reaction intermediates. We drew these conclusions based on total organic carbon (TOC) measurements.

This study investigates the viability of TiO 2 as a high- k material in metal-insulator-metal (MIM) capacitors, essential components influencing semiconductor memory device performance. Traditional materials like ZrO 2 and HfO 2 face intrinsic limitations, prompting exploration into TiO 2 's potential, particularly in its rutile crystalline structure with a remarkable dielectric constant of 170. Leveraging atomic layer deposition (ALD), TiO 2 emerges as a promising candidate for MIM capacitors. The study focuses on the practical application of a MoO 2 electrode in TiO 2 dielectric film MIM capacitors, demonstrating its potential to induce rutile crystallization in both MoO 2 and TiO 2 while suppressing morphology degradation. Insights into the mechanism of TiO 2 rutile crystallization contribute to the development of an optimized MoO 2 /TiO 2 -based MIM capacitor, offering a significant advancement in addressing challenges and improving the performance of next-generation semiconductor memory devices. [Display omitted] • Developing the in-situ rutile crystallization process of MoO x and TiO 2 • Inducing simultaneous crystallization of MoO 2 and TiO 2 within a desirable thickness range • Effectively suppressing morphology degradation of MoO x • The practical application of a MoO 2 electrode in TiO 2 dielectric film MIM capacitors • Achieving a highly scalable metal-insulator-metal structure of t ox of 0.328 nm [ABSTRACT FROM AUTHOR]

Amounts of oxygen vacancies in MoO x was controllably orchestrated to exert a comprehensive influence on the CO 2 hydrogenation reaction. [Display omitted] • The catalytic performance of MoO x catalysts exhibited a clear volcano-shaped trend, emphasizing the impact of oxygen vacancies on CO 2 conversion and CO formation. • Steady-state kinetics revealed a significant enhancement in CO 2 activation at optimal oxygen vacancy concentrations. • The catalytic reaction followed a formate pathway, with the hydrogenation of formate identified as the rate-determining step over MoO x catalysts. Oxygen vacancies in oxides are core parameters determining the catalytic performance in various reactions. This study investigated the influence of oxygen vacancies of MoO x catalysts on the reverse water gas shift (RWGS) reaction to gain a deep insight into the structure–function relationship. A distinct volcano-shaped trend was observed among MoO x catalysts with different amounts of oxygen vacancies. Through comprehensive characterizations and steady-state kinetic analysis, an optimal concentration of oxygen vacancies was identified to not only facilitate the adsorption and activation of CO 2 but also restrain the formation of by-product CH 4. In-situ characterizations combined with DFT calculations uncovered a formate-involved reaction pathway over the oxygen vacancies structured MoO x catalyst, with the hydrogenation of formate identified as the rate-determining step. These findings not only showcase the potential of Mo-based oxides in CO 2 hydrogenation reactions but also provide fundamental insights into the role of oxygen vacancies in shaping catalytic behavior. [ABSTRACT FROM AUTHOR]

In this study, molybdenum oxide nanostructures (MoO 3 NSs) were effectively synthesized through a simple, low-cost, surfactant-free, low-temperature, and scalable chemical co-precipitation method and investigated their synergistic effect with annealing temperature on energy storage applications for the first time. Herein, we have reported a phase transition of MoO 3 NSs from hexagonal to orthorhombic after the annealing temperature varied from 100°C to 500°C at constant time. Additionally, the resultant NSs were thoroughly examined for their physio-chemical characteristics, which revealed the stable phase formation of the MoO 3 NSs, respectively. Furthermore, the electroactive MoO 3 NSs were pasted on Ni-foam substrate (M@NF), and electrochemical properties were evaluated using a three-electrode setup at room-air temperature in 1 M KOH aqueous electrolyte across the potential range of 0 V to 0.786 V. As a result, the M@NF-5 electrode exhibited an impressive specific capacitance of 976.84 F g−1 at a scan rate of 1 mV s−1, a higher energy density of 73.69 Wh kg−1, and a power density of 655 W kg−1 at 5 mA g−1. The non-linear galvanostatic charge-discharge (GCD) profile aligns well with the cyclic voltammetry (CV) analysis. Both CV and GCD techniques confirm the pseudocapacitive behavior, with 83% capacitive retention observed after 2000 cycles. The fabricated symmetric device (M@NF-5//M@NF-5) exhibits enhanced electrochemical performance with a specific capacitance of 67.35 F g−1 at 5 mA g−1 and with an energy density of 18 Wh kg−1, and a power density of 1750 W kg−1 at a specific current. These findings underscore the potential of chemically deposited α-MoO 3 as an auspicious material for use in supercapacitor applications. [Display omitted] [ABSTRACT FROM AUTHOR]

The catalytic activity of molybdenum and tungsten oxides formed in situ from their carbonyls was studied in the hydroprocessing of diphenyl ether (DPE) for the first time. The MoO x and WO x catalysts obtained were characterized by XRD, XPS, HRTEM, EDX, Raman spectroscopy, and NH 3 TPD. The effect of various parameters on the substrate conversion and the yields of products was investigated. Oxygen vacancies (OVs) on the catalyst surface were found to be active sites in the DPE hydroprocessing. MoO x was more active than WO x due to more OVs on the surface of the catalyst. Benzene was obtained as a major product over both of catalysts with a highest yield of 87% (99% DPE conversion) over MoO x and of 69% (96% DPE conversion) over WO x. [Display omitted] • In situ formed MoO x and WO x was studied in the hydroprocessing of diphenyl ether. • Oxygen vacancies were found to be active sites in the process studied. • The evolution of oxygen vacancies on the catalyst surface was shown. • Benzene was obtained with the highest yield of 87% over MoO x and 69% – over WO x. • The catalytic activity of the MoO x and WO x is maintained after 5 test runs. [ABSTRACT FROM AUTHOR]

Aqueous zinc-ion batteries (AZIBs) have gained significant attention due to their high safety profile and potential for cost-effectiveness. However, the lack of rapid kinetic and durable cycling cathode materials has impeded the development of AZIBs. The present study suggests the implementation of synthesizing nano-H x MoO 3 through a H+-based intercalation strategy in nano α-MoO 3 to effectively address these concerns. The electrochemical kinetics of H x MoO 3 exhibit significant improvement, as shown by data analyses of cyclic voltammetry, electrochemical impedance spectroscopy, and galvanostatic intermittent titration technique. In addition, the results of the charge and discharge tests show that the H x MoO 3 cathode has significantly less capacity degradation during the first discharge than MoO 3 and a more stable structure. As a result, the H x MoO 3 cathode demonstrated outstanding electrochemical performance, exhibiting discharge capacities of 215 and 158 mAh g−1 at current densities of 0.5 and 5 A g−1, as comparison the MoO 3 cathode only have 189 and 142 mAh g−1. Moreover, the H x MoO 3 cathode maintained 74% of its initial capacity after 100 cycles at a current density of 0.5 A g−1. Even after 2000 cycles at a current density of 5 A g−1, H x MoO 3 maintains 44% of its original capacity, whereas MoO 3 only retains 30%. [Display omitted] • For the first time, MoO 3 with pre-inserted H+ was used as a cathode material for aqueous zinc ion batteries. • The pre-inserted embedded H+ greatly reduces the structural changes in the first cycle of the material and enhances the stability of the material. • Nano- and intercalation engineering synergistically enhances the electrochemical kinetics of the material. [ABSTRACT FROM AUTHOR]

[Display omitted] • The well-designed amorphous MoO x loaded on N-doped carbon layer (NC)-modified SiO 2 was successfully fabricated. • The amorphous structure of MoO x promotes the activation of H 2 O 2 into the active oxygen species. • MoO x @NC@SiO 2 depicts outstanding performance for oxidation desulfurization. Transition-metal oxides (TMOs) are good catalyst candidates for oxidation desulfurization (ODS) reaction, and its excellent dispersion in carriers could exert great influence on its catalytic performance. However, improving its catalytic activity still remains challenging. Herein, the amorphous molybdenum oxide (MoO x) was synthesized as the active sites for ODS reaction. Via a facile adsorption-pyrolysis approach, the amorphous MoO x was dispersedly immobilized onto N-doped carbon layer (NC)-encapsulated SiO 2 using zinc pyridine porphyrin (ZnTPyP) and phosphomolybdic acid (PMo 12)-modified SiO 2 nanocomposites as precursor, obtaining the MoO x @NC@SiO 2 catalyst. Owing to the wonderful pre-dispersion of Mo sources on the precursor leaded by the electrostatic interaction and spacial effect, the confinement effect of the derived carbon matrix, and the strong Mo-N bonds, the growth of MoO x crystal could be inhibited in pyrolysis procedure, ensuring the amorphous structure and good dispersion of MoO x species on SiO 2. The as-prepared MoO x @NC@SiO 2 exhibits excellent oxidation desulfurization (ODS) performances, and could promote the complete oxidation of DBT in model fuel into DBTO 2 at the theoretical O/S molar ratio of 2, due to the perfect activation of all oxygen atoms of H 2 O 2 by the amorphous MoO x. In addition, a plausible ODS mechanism over MoO x @NC@SiO 2 is depicted to be the •OH radicals. Moreover, MoO x @NC@SiO 2 still displays an outstanding reusability over at least 10 cycles owing to the encapsulation of NC layers and the strong Mo-N bonds. Therefore, this work provides a promising catalyst for industrial ODS application, and opens up a new avenue for developing the amorphous TMOs catalysts. [ABSTRACT FROM AUTHOR]

It is essential and still remains a big challenge to obtain fast-charge anodes with large capacities and long lifespans for Li-ion batteries (LIBs). Among all of the alternative materials, molybdenum trioxide shows the advantages of large theoretical specific capacity, distinct tunnel framework, and low cost. However, there are also some key shortcomings, such as fast capacity decaying due to structural instability during Li insertion and poor rate performance due to low intrinsic electron conductivity and ion diffusion capability, dying to be overcome. A unique strategy is proposed to prepare Ti- h -MoO 3- x @TiO 2 nanosheets by a one-step hydrothermal approach with NiTi alloy as a control reagent. The density functional theory (DFT) calculations indicate that the doping of Ti element can make the hexagonal h-MoO 3- x material show the best electronic structure and it is favor to be synthesized. Furthermore, the hexagonal Ti-h-MoO 3- x material has better lithium storage capacity and lithium diffusion capacity than the orthogonal α-MoO 3 material, and its theoretical capacity is more than 50% higher than that of the orthogonal α-MoO 3 material. Additionally, it is found that Ti-h-MoO 3- x @TiO 2 as an anode displays extremely high reversible discharge/charge capacities of 1326.8/1321.3 mAh g -1 at 1 A g -1 for 800 cycles and 611.2/606.6 mAh g -1 at 5 A g -1 for 2000 cycles. Thus, Ti-h-MoO 3- x @TiO 2 can be considered a high-power-density and high-energy-density anode material with excellent stability for LIBs.

The title compound, (C 2 H 10 N 2 ) 2 [(C 10 H 12 N 2 O 8 )(MoO 3 ) 2 ]·4H 2 O, which crystallizes in the monoclinic C 2/ c space group, was obtained by mixing molybdenum oxide, ethyl-enedi-amine and ethyl-enedi-amine-tetra-acetic acid (H 4 edta) in a 2:4:1 ratio. The complex anion contains two MoO 3 units bridged by an edta 4- anion. The midpoint of the central C-C bond of the edta 4- anion is located on a crystallographic inversion centre. The independent Mo atom is tridentately coordin-ated by a nitro-gen atom and two carboxyl-ate groups of the edta 4- ligand, together with the three oxo ligands, producing a distorted octa-hedral coordination environment. In the three-dimensional supra-molecular crystal structure, the dinuclear anions, the organo-ammonium counter-ions and the solvent water mol-ecules are linked by N-H⋯O w , N-H⋯O edta and O-H⋯O hydrogen bonds., (© Yaffa et al. 2024.)

Exploiting pseudocapacitance in rationally engineered nanomaterials offers greater energy storage capacities at faster rates. The present research reports a high-performance Molybdenum Oxynitride (MoON) nanostructured material deposited directly over stainless-steel mesh (SSM) via reactive magnetron sputtering technique for flexible symmetric supercapacitor (FSSC) application. The MoON/SSM flexible electrode manifests remarkable Na + -ion pseudocapacitive kinetics, delivering exceptional ≈881.83 F g -1 capacitance, thanks to the synergistically coupled interfaces and junctions between nanostructures of Mo 2 N, MoO 2 , and MoO 3 co-existing phases, resulting in enhanced specific surface area, increased electroactive sites, improved ionic and electronic conductivity. Employing 3D Bode plots, b-value, and Dunn's analysis, a comprehensive insight into the charge-storage mechanism has been presented, revealing the superiority of surface-controlled capacitive and pseudocapacitive kinetics. Utilizing PVA-Na 2 SO 4 gel electrolyte, the assembled all-solid-state FSSC (MoON/SSM||MoON/SSM) exhibits impressive cell capacitance of 30.7 mF cm -2 (438.59 F g -1 ) at 0.125 mA cm -2 . Moreover, the FSSC device outputs a superior energy density of 4.26 µWh cm -2 (60.92 Wh kg -1 ) and high power density of 2.5 mW cm -2 (35.71 kW kg -1 ). The device manifests remarkable flexibility and excellent electrochemical cyclability of ≈91.94% over 10,000 continuous charge-discharge cycles. These intriguing pseudocapacitive performances combined with lightweight, cost-effective, industry-feasible, and environmentally sustainable attributes make the present MoON-based FSSC a potential candidate for energy-storage applications in flexible electronics., (© 2023 Wiley‐VCH GmbH.)

This article discusses the synthesis of molybdenum oxide and sulfide nanoparticles using an organometallic approach at room temperature. The authors highlight the ability to control the shape and size of these nanoparticles under mild reaction conditions. While previous research has focused on late transition metals, this study explores the use of early transition metal complexes for the preparation of oxide and sulfide nanoparticles. The results demonstrate the successful synthesis of stable colloidal nanoparticles with a diameter of less than 10 nm. The authors declare no conflicts of interest and acknowledge V. Collière for the TEM measurements. [Extracted from the article]

The Mo-doping KIT-6 photocatalyst (MoK) was synthesized by a convenient way with one-pot method and annealing strategy. DBT was converted to DBTO 2 in a short period of time under visible light due to the 3D mesoporous structure and appropriate band gap of MoK. [Display omitted] • The Mo-doping KIT-6 was synthesized by one-pot method and annealing strategy. • The 3D mesoporous structure enhances light absorption and mass transfer of catalyst. • Appropriate band structure promotes the separation of photogenarated charge carriers. • The electron transfer and photoelectrochemical properties of catalyst was studied. • Deep desulfurization was realized in a short period of time under visible light. A series of Mo-KIT-6 catalysts were developed to photocatalytic oxidize sulfur compounds and promote effective product separation in a photocatalytic extraction oxidative desulfurization (PEODS) system with visible light, extractant [Omim]PF 6 and oxidant H 2 O 2. Morphological and pore structure characterization showed that Mo-KIT-6 possessed significant three-dimensional mesoporous structure and large specific surface area which enhanced mass transfer effect and be provided good dispersion of active sites. Doping of Mo enhanced the light absorption and promoted the photogenerated electron hole pair separation, resulting the improvement of the ability of photocatalytic oxidation desulfurization. Among the catalysts, the 15 wt% Mo doping KIT-6 revealed the best desulfurization performance and reached 100 % sulfur removal in 25 min. The circulation experiment proved that the good circulation performance and stability of the photocatalyst within 5 cycles. Radical scavenger experiments and ESR analysis confirmed that OH and h+ played a major role in the reaction. Furthermore, a possible photocatalytic desulfurization mechanism was proposed. [ABSTRACT FROM AUTHOR]

[Display omitted] • First-time synthesis of MoO 3 /PAN composite membrane via electrospinning. • Efficient green synthesis of Ag and Cu NFM under UV irradiation. • Ag NFM: surface area + 25.89 %, WCA −15 %; Cu NFM: surface area + 30.27 %, WCA –33.75 % • Sustained release of Ag and Cu in 7 Days. • Comparative analysis of antibacterial efficacy against E.coli and B.subtilis bacteria. The development of hybrid composite antibacterial agents for wound dressing has garnered significant attention due to their remarkable antibacterial efficacy and their potential to mitigate microbial resistance. In this study, we present an approach to designing and fabricating wound dressing membranes utilizing MoO 3 /PAN hybrid composites through electrospinning. Subsequently, we enhanced the membrane's effectiveness by introducing silver (Ag-MoO 3 /PAN) and copper (Cu-MoO 3 /PAN) into the matrix via a rapid (within one minute) green synthesis method under UV irradiation. Initially, we discuss the morphological characteristics and structural attributes of the resulting membranes. Subsequent investigation explores the antibacterial mechanisms of MoO 3 , Ag+, and Cu+ revealing that the incorporation of silver and copper substantially enhanced antibacterial activity. Silver nanoparticles into the composite material significantly enhanced its antibacterial effectiveness, particularly against Escherichia coli , while copper nanoparticles exhibited an even more substantial inhibitory effect, approximately 28.12 % greater compared to silver nanoparticles, and 21.23 % greater than pristine molybdenum oxide nanofiber against Bacillus subtilis. Additionally, we elucidate the surface properties, noting that the introduction of silver increases the surface area of the composite membrane by 25.89 % while copper increases the surface area by 30.27 % compared to the pristine MoO 3 /PAN membrane. Furthermore, we observe a 15 %, and 33.75 % reduction in WCA for the Ag-MoO 3 /PAN membrane and Cu-MoO 3 /PAN membrane respectively, indicating improved hydrophilicity. Finally, we analyze the release behavior of the Ag+ and Cu+ from pristine nanofiber membranes. Our findings demonstrate an initial burst in silver release of about 70 % within the first 7 h, followed by a 33.52 % reduction and then a sustained release pattern over a period of 7 days, while for copper 41 % increased within the first 7 h, followed by gradually increased release pattern over a period of 7 days. [ABSTRACT FROM AUTHOR]

The pursuit of addressing the escalating and crucial energy demands of humanity has served as an inspiration for the discovery and creation of advanced nanomaterials used to facilitate convenient and sustainable energy-storing materials and systems. A cost-effective and environmentally safe nanocomposite was synthesized through the incorporation of molybdenum oxide (MoO 3) and 2-D graphitic carbon nitride (g-CN) nanosheets by hydrothermal route. The C s of the g-CN, MoO 3 and MoO 3 /g-CN at 10 mV s−1 were measured to be 212.146, 350.49 and 693.56 F g−1 respectively, in a 2 M KOH by CV. The C s for g-CN, MoO 3 and MoO 3 /g-CN nanocomposite at 1 A g−1 were displayed as 852, 688 and 283 F g−1 by GCD. The E d of the nanocomposite was significantly elevated to 35.4 Wh kg−1 when subjected to P d of 273 W kg−1. MoO 3 /g-CN nanocomposites have advantageous characteristics for energy-storing devices due to their notable increased surface area, enhanced electric conduction, and synergistic effect of MoO 3 and g-CN. The utilization of MoO 3 /g-CN nanocomposite presents a viable and pragmatic approach to address the prevailing energy problem by serving as an effective energy storage option. [Display omitted] [ABSTRACT FROM AUTHOR]

The low intrinsic catalytic performance and stability are the two dominant obstacles for alkaline hydrogen evolution reaction (HER) electrocatalyst. Herein, amorphous molybdenum oxide (MoO x) has been introduced to rhodium hierarchical nanosheets (MoO x Rh-HNS) at atomic level efficiently reducing the barrier for hydrogen spillover from Rh to MoO x ; thereby, MoO x Rh-HNS exhibit superior HER activity with mass activity of 23.9 A mg noble metal −1 at overpotential of 200 mV, which is boosted by 10.8- and 14.9-fold with relative to Rh-HNS and Pt/C in alkaline media, respectively. Meanwhile, Tafel slope is as low as 22.5 mV dec−1 for MoO x Rh-HNS revealing a hydrogen-spillover-involving HER mechanism proved by the electrochemical test as well as operando electrochemical impedance spectroscopy. Density functional theory calculation indicates the adsorbed hydrogen on MoO x Rh promotes the water dissociation and balances the hydrogen binding strength to a moderate level. Simultaneously, the hierarchical nanosheet structure contributes a robust HER stability at 500 mA cm−2. This work offers a new methodology to construct a high-performance alkaline HER electrocatalyst with industrial-level current density. [Display omitted] • MoO x has been incorporated into Rh hierarchical nanosheets at atomic level. • MoO x Rh-HNS exhibit a 14.9-fold higher mass activity than Pt/C at –0.2 V vs. RHE. • Hydrogen spillover is found to assist HER catalysis for MoO x Rh-HNS. [ABSTRACT FROM AUTHOR]

[Display omitted] In the present study, a new magnetic acid solid catalyst composed of an agro-industrial waste (rice husk ash-RHA) magnetized with cobalt ferrite (CoFe 2 O 4) and impregnated with MoO 3 was synthesized and applied in the methyl transesterification reaction of waste frying oil (WFO) for biodiesel production. The catalyst was synthesized by wet impregnation method and characterized by the following techniques: surface acidity, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy dispersion X-ray spectroscopy (EDS), and vibrating sample magnetometer (VSM). The one variable at time (OVAT) technique was used to optimize the variables of the transesterification reaction in the following ranges: temperature (130.0–170.0 °C), methanol:oil molar ratio (10:1–50:1), catalyst amount (2.0–10.0 wt%), and reaction time (1.0–5.0 h). The results demonstrate that the application of the MoO 3 /RHA-CoFe 2 O 4 synthesized catalyst resulted in the attainment a biodiesel with ester content of 94.6 % under the optimized reaction conditions: temperature of 160.0 °C, methanol:oil molar ratio of 20:1, catalyst amount of 6.0 wt%, and reaction time of 3.0 h. The biodiesel produced was characterized and presented physicochemical properties in accordance with the limits established by the international standards ASTM D6751 and EN 14214. The kinetic study of the transesterification process revealed that the pseudo-first order model is the most suitable with an activation energy of 27.3 kJ mol−1. In addition, the catalyst showed bifunctional character (catalytic and magnetic), as well as high catalytic stability after ten reaction cycles, maintaining the production of biodiesel with ester content above 70.0 %, indicating its high potential for development and application. [ABSTRACT FROM AUTHOR]

Light is an attractive source of energy for regulating stimulus-responsive chemical systems. Here, we use light as a gating source to control the redox state, the localized surface plasmonic resonance (LSPR) peak, and the structure of molybdenum oxide (MoO 3 ) nanosheets, which are important for various applications. However, the light excitation is not that of the MoO 3 nanosheets but rather that of pyranine (HPTS) photoacids, which in turn undergo an excited-state proton transfer (ESPT) process. We show that the ESPT process from HPTS to the nanosheets and the intercalation of protons within the MoO 3 nanosheets trigger the reduction of the nanosheets and the broadening of the LSPR peak, a process that is reversible, meaning that in the absence of light, the LSPR peak diminishes and the nanosheets return to their oxidized form. We further show that this reversible process is accompanied by a change in the nanosheet size and morphology.

In this paper, the successful synthesis of bare molybdenum oxide (MoO 3) nanobelts using a one-step hydrothermal method without the use of surfactants is reported. Additionally, ZnO nanoflakes are synthesized through a green method, employing ginger extract, owing to the presence of phenolic compounds found in ginger, mainly gingerols , shogaols , and paradols. Furthermore, the fabrication of MoO 3 /ZnO nanocomposites using an uncomplicated and readily accessible ultrasonication method is presented. Also, the effects of hydrothermal reaction time (12, 24, and 36 h) and the molar ratio of MoO 3 nanobelts (NBs) to ZnO nanoflakes (2:1, 1:1, and 1:2) are investigated on the properties of synthesized MoO 3 nanostructures and MoO 3 /ZnO composites, respectively. The results declare that the optical and structural properties, morphology, and stability of the MoO 3 are influenced by hydrothermal reaction time significantly and the uniform MoO 3 nanobelts are obtained in a reaction time of 24 h. Also, the formation of nanocomposites with different ratios of MoO 3 nanobelt and ZnO nanoflakes by ultrasonication leads to forming uniform distributions of ZnO nanoparticles on the surface of MoO 3 structures. Indeed, the ultrasonication condition causes the transformation of the biphasic MoO 3 structure to a single-phase MoO 3 in the composites. Furthermore, the optical properties of MoO 3 nanobelts including the reflection especially in the UV region, and also the bandgap energies of the NBs are affected by providing the nanocomposites, and the bandgap energies change from 2.94 eV (bare MoO 3 nanobelts) to 3.18 eV (nanocomposites). The reasons for the phenomena are explained in the paper. These insights into the controlled synthesis of MoO 3 nanostructures and MoO 3 /ZnO nanocomposites pave the way for potential applications in fields such as advanced sensors, optoelectronics, and energy-efficient devices. [Display omitted] • Synthesis of MoO 3 nanobelts and consider the effects of hydrothermal reaction time. • Synthesis of ZnO nanoflakes (NFs) by a green method using the ginger extract. • Effects of NPs molar ratios on MoO 3 /ZnO nanocomposites provided by ultrasonication. • Transformation (bi-to single-phase MoO 3) in the composites. • Significant effects on optical properties including reflectance and bandgap energy. [ABSTRACT FROM AUTHOR]

The production of propylene from readily available propane sources is of great importance as it serves as a crucial building block for producing numerous value-added chemicals. Oxidative dehydrogenation of propane with carbon dioxide (ODPC) has been proposed as a viable and eco-friendly approach for simultaneous propylene production and carbon dioxide reduction. In this study, ZnO x catalysts were prepared by supporting them on a range of molybdenum–zirconium (Mo–Zr) mixed–oxides with varying Mo contents, aiming to utilize them for ODPC applications. The incorporation of suitable quantities of Mo in zirconium dioxide (ZrO 2) supports increases the surface concentration and enhances the dispersion of ZnO x , thereby demonstrating promotional effects on the surface properties of the supported ZnO x catalysts. Notably, the ZnO x catalyst supported on a Mo–Zr mixed–oxide, with an optimized Mo content, exhibits a propane conversion rate more than two-fold higher than that of the catalyst without Mo in ODPC. Furthermore, the introduction of Mo into the ZrO 2 supports effectively inhibits the formation of coke by suppressing the cleavage of C–C bonds in propane. In comparison, the supported ZnO x catalysts with higher Zn loadings, show that a Mo–Zr mixed–oxide support effectively suppresses the formation of bulk ZnO x more than an unmodified ZrO 2 support, leading to improved ODPC performance. The promoting effects of Mo emphasize the potential of utilizing mixed–oxide supports for ZnO x catalysts in ODPC, demonstrating a promising opportunity for enhancing catalytic performance. [Display omitted] • Investigation of oxidative dehydrogenation of propane using CO 2 over ZnO x /Mo–Zr. • Enhancement in surface concentration of ZnO x on Mo–Zr supports by presence of Mo. • Improvement in dispersion of ZnO x on Mo–Zr mixed–oxides by incorporation of Mo. • Enhanced catalytic performance of ZnO x /Mo–Zr compared to that of ZnO x /ZrO 2. [ABSTRACT FROM AUTHOR]

In this work, a new MoO 3 @Mo 2 CT x nanocomposite was prepared from two-dimensional (2D) Mo 2 CT x MXene by in situ oxidization in air, which exhibited wonderful lithium-storage performance as anodes of lithium-ion batteries (LIBs). The precursor Mo 2 CT x was synthesized from Mo 2 Ga 2 C by selective etching of NH 4 F at 180 °C for 24 h. Thereafter, the Mo 2 CT x was oxidized in air at 450 °C for 30 min to obtain MoO 3 @Mo 2 CT x nanocomposite. In the composite, in situ generated MoO 3 nanocrystals pillar the layer structure of Mo 2 CT x MXene, which increases the interlayer space of Mo 2 CT x for Li storage and enhances the structure stability of the composite. Mo 2 CT x 2D sheets provide a conductive substrate for MoO 3 nanocrystals to enhance the Li + accessibility. As anodes of LIBs, the final discharge specific capacity of the MoO 3 @Mo 2 CT x composite was 511.1 mAh g -1 at a current density of 500 mA g -1 after 100 cycles, which is about 36.7 times that of pure Mo 2 CT x MXene (13.9 mAh g -1 ) and 3.2 times that of pure MoO 3 (159.9 mAh g -1 ). In the composites, both Mo 2 CT x and MoO 3 provide high lithium storage capacity and can enhance the performance of each other. Moreover, this composite can be made by a facile method of in situ oxidation. Therefore, the MoO 3 @Mo 2 CT x MXene nanocomposite is a promising anode of LIB with high performance., (© 2024 IOP Publishing Ltd.)

Doping is one of the most difficult technological challenges for realizing reliable two-dimensional (2D) material-based semiconductor devices, arising from their ultrathinness. Here, we systematically investigate the impact of different types of nonstoichiometric solid MO x (M are W or Mo) dopants obtained by oxidizing transition metal dichalcogenides (TMDs: WSe 2 or MoS 2 ) formed on graphene FETs, which results in p -type doping along with disorders. From the results obtained in this study, we were able to suggest an analytical technique to optimize the optimal UV-ozone (UVO) treatment to achieve high p -type doping concentration in graphene FETs (∼2.5 × 10 13 cm -2 in this study) without generating defects, mainly by analyzing the time dependency of D and D ' peaks measured by Raman spectroscopy. Furthermore, an analysis of the structure of graphene sheets using TEM indicates that WO x plays a better protective role in graphene, compared to MoO x , suggesting that WO x is more effective for preventing the degradation of graphene during UVO treatment. To enhance the practical application aspect of our work, we have fabricated a graphene photodetector by selectively doping the graphene through oxidized TMDs, creating a p - n junction, which resulted in improved photoresponsivity compared to the intrinsic graphene device. Our results offer a practical guideline for the utilization of surface charge transfer doping of graphene toward CMOS applications.