Search

[Display omitted] • An electrocatalyst based on the Pt-MoO 3 /NiMoO 4 NRs has been fabricated for industrial-grade water splitting. • The electrolyzer using Pt-MoO 3 /NiMoO 4 NRs electrodes only required 1.55 V to achieve 10 mA cm−2. • Density functional theory calculations proved that the good synergy of the MoO 3 /NiMoO 4 and Pt benefited their catalytic performance. A new catalyst has been developed that utilizes molybdenum oxide (MoO 3)/nickel molybdenum oxide (NiMoO 4) heterostructured nanorods coupled with Pt ultrafine nanoparticles for the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) toward industrial-grade water splitting. This catalyst has been synthesized using a versatile approach and has shown to perform better than noble-metals catalysts, such as Pt/C and RuO 2 , at industrial-grade current level (≥1000 mA·cm−2). When used simultaneously as a cathode and anode, the proposed material yields 10 mA·cm−2 at a remarkably small cell voltage of 1.55 V and has shown extraordinary durability for over 50 h. Density functional theory (DFT) calculations have proved that the combination of MoO 3 and NiMoO 4 creates a metallic heterostructure with outstanding charge transfer ability. The DFT calculations have also shown that the excellent chemical coupling effect between the MoO 3 /NiMoO 4 and Pt synergistically optimize the charge transfer capability and Gibbs free energies of intermediate species, leading to remarkably speeding up the reaction kinetics of water electrolysis. [ABSTRACT FROM AUTHOR]

[Display omitted] Zinc metal anodes in aqueous electrolytes commonly face challenges such as dendrite growth and undesirable side reactions, limiting their application in the field of aqueous zinc-ion batteries (AZIBs) for energy storage. Drawing inspiration from industrial practices involving molybdenum salt solutions for metal modification, a polyoxometalate solution was formulated as a passivation solution for zinc anodes (referred to as MO solution). The formed passivation layer, referred to as the MO layer, exhibited a uniform and protective nature with a thickness of approximately 10 μm. The experimental results demonstrated that this passivation layer effectively suppressed side reactions at the zinc anode interface, as evidenced by lower corrosion current density for MO-Zn anodes. Additionally, the newly plated Zn was uniformly deposited atop the MO layer, ensuring coating integrity and inhibiting dendrite growth. As a result, under more demanding conditions such as a larger current of 8 mA cm−2, the MO-Zn anode displayed an extended cycle life exceeding 420 h in a symmetric battery, with an overpotential as low as 98 mV. This performance significantly outperformed that of commercially available pure Zn foils (with a cycle life of 60 h and an overpotential of 192 mV). Notably, a self-made Na-doped V 2 O 5 served as the cathode (referred to as NaVO), forming the MO-Zn//NaVO full battery. Even under high current test conditions of 2 A/g, the specific capacity of the MO-Zn//NaVO full battery remained substantial at 152.83 mAh/g after 1000 cycles. Furthermore, pouch batteries assembled with NaVO//MO-Zn successfully illuminated small bulbs. This study offers a viable optimization strategy for AZIB anodes and demonstrates the potential of using polyoxometalate solution for etching zinc anodes to inhibit dendrite growth and interfacial corrosion of zinc metal anodes. [ABSTRACT FROM AUTHOR]

[Display omitted] • MoAl 1-x B MBene is demonstrated to be a robust support for loading Ru nanoparticles. • Ru/MoAl 1-x B achieves the superior catalytic performance towards hydrogen generation. • Mechanism of AB hydrolysis over Ru/MoAl 1-x B is systematically investigated. • This is a first example to demonstrate MBene for boosting AB hydrolysis. The coordination between carrier and active metal is critical to the catalytic efficiency of ammonia borane (AB) hydrolysis reaction. In the present study, we report a new type of catalytic support based on molybdenum boride (MBene) MoAl 1-x B and demonstrate that the effective combination of MoAl 1-x B with Ru nanoparticles can realize the significantly enhanced performance for hydrogen generation. Owing to the efficient activation and dissociation of reactants, the optimal Ru/MoAl 1-x B catalyst achieves the large turnover frequency of 494 mol H2 mol Ru -1 min−1, high hydrogen generation rate of 119817 mL min−1 g Ru -1 and favorable apparent activation energy of 39.2 kJ mol−1 for the catalytic hydrolysis of AB under alkaline-free condition. The isotopic test suggests the cleavage of O H bond in H 2 O is the rate-determining step for hydrolysis reaction, while the fracture of B–H bond in AB is also well revealed by attenuated total reflectance (ATR)-Fourier transform infrared (FTIR) spectroscopy. Significantly, the flexible on-demand hydrogen generation is achieved by using chemical switches for on–off AB hydrolysis. This study provides a new support platform based on two-dimensional MBene to exploit efficient catalysts to boost AB dehydrogenation. [ABSTRACT FROM AUTHOR]

Novel charge distribution regulation strategy for Mo 2 C, the relationships of Interface-Structure-Property in heterostructures were clarified, facilitating efficient adsorption-catalysis of Li 2 S x (1≤x≤4) [Display omitted] • A novel electronic distribution regulation strategy (Mo-Mo 2 C heterostructure) for molybdenum carbide was developed. • The relationship of the heterointerfaces-structure–property in Mo-Mo 2 C has been clarified. • The modulation of the intrinsic electronic distribution of Mo 2 C results higher adsorption energy for lithium polysulfides (LiPSs) and stronger Mo-S bonding strength. • The sulfur cathode with C@Mo-Mo 2 C an excellent high-rate cyclic performance accompanied by capacity decay rate of 0.08 % per cycle after 400 cycles at 2 C. Heterostructure engineering is considered a crucial strategy to modulate the intrinsic charge transfer behavior of materials, enhance catalytic activity, and optimize sulfur electrochemical processes. However, parsing the role of heterogeneous interface-structure–property relationships in heterostructures is still a key scientific issue to realize the efficient catalytic conversion of polysulfides. Based on this, molybdenum carbide (Mo 2 C) was successfully partial reduced to molybdenum metal (Mo) via a thermal reduction at high-temperature and the typical Mo-Mo 2 C-based Mott-Schottky heterostructures were simultaneously constructed, which realized the modulation of the electronic structure of Mo 2 C and optimized the conversion process of lithium polysulfides (LPS). Compared with single molybdenum carbide, the modulated molybdenum carbide acts as an electron donor with stronger Mo-S bonding strength as well as higher polysulfide adsorption energy, faster Li 2 S conversion kinetics, and greatly facilitates the adsorption → catalysis process of LPS. As a result, yolk-shell Mo-Mo 2 C heterostructure (C@Mo-Mo 2 C) exhibits excellent cycling performance as a sulfur host, with a discharge specific capacity of 488.41 mAh g−1 for C@Mo-Mo 2 C/S at 4 C and present an excellent high-rate cyclic performance accompanied by capacity decay rate of 0.08 % per cycle after 400 cycles at 2 C. Heterostructure-acting Mo 2 C electron distribution modulation engineering may contributes to the understanding of the structure-interface-property interaction law in heterostructures and further enables the efficient modulation of the chemical behavior of sulfur. [ABSTRACT FROM AUTHOR]

[Display omitted] Developing a high-activity and low-cost catalyst to reduce the anodic overpotential is essential for hydrogen production from water splitting. In this work, a hetero-structured Co 7 Fe 3 /Mo 2 C@C catalyst has been developed to efficiently catalyze oxygen evolution reaction (OER), the overpotential (ƞ 10) of Co 7 Fe 3 /Mo 2 C@C-catalyzed OER with current density of 10 mA/cm2 is about 254 mV, substantially lower than the counterparts of Co 7 Fe 3 @C-catalyzed OER (ƞ 10 , 308 mV) and Mo 2 C@C-catalyzed OER (ƞ 10 , 439 mV), close to that of OER catalyzed by commercial RuO 2. The mechanistic studies reveal that the distinct electron transfer across the Co 7 Fe 3 /Mo 2 C interface results in electron-deficient Co 7 Fe 3 , which has been identified as the highly active catalytic sites. Density functional theory (DFT) calculations manifest that Mo 2 C induces a distinct decrease in electron density on Co 7 Fe 3 and upgrades the d -band centers of Co and Fe in Co 7 Fe 3 towards Fermi energy level, thus substantially lowering the energy barrier of the rate-determining reaction step and conferring significantly improved OER activity on the Co 7 Fe 3 /Mo 2 C@C catalyst. [ABSTRACT FROM AUTHOR]

[Display omitted] Single-atom catalysts (SACs) have attracted extensive attention in the field of catalysis due to their excellent catalytic ability and enhanced atomic utilization, but the multi-mode single-atom nanozymes for biosensors remain a challenging issue. In this work, iron-doped carbon dots (Fe CDs) were loaded onto the edges and pores of Mo SACs with nanoflower morphology; accordingly, a composite material Fe CDs/Mo SACs was prepared successfully, which improves the catalytic performance and develops a fluorescence mode without changing the original morphology. The steady-state kinetic data indicates that the material prepared have better affinity for substrates and faster reaction rates under optimized conditions. The specific kinetic parameters K m and V max were calculated as 0.39 mM and 7.502×10−7 M·s−1 respectively. The excellent peroxidase-like activity of Fe CDs/Mo SACs allows H 2 O 2 to decompose into •OH, which in turn oxidizes colorless o -phenylenediamine (OPD) to yellow 2,3-diaminophenazine (DAP). At the same time, the fluorescence signal of Fe CDs/Mo SACs quenches obviously by DAP at 460 nm through internal filtration effect (IFE), while the characteristic fluorescence response of DAP gradually increases at 590 nm. Based on this sensing mechanism, a sensitive and accurate dual-mode (colorimetric and ratiometric fluorescent) sensor was constructed to detect H 2 O 2 and uric acid, and the rate of recovery and linearity were acceptable for the detection of UA in human serum and urine samples. This method provides a new strategy for rapid and sensitive detection of UA, and also broadens the development of SACs in the field of biosensors. [ABSTRACT FROM AUTHOR]

The synthesized Ru-MoNi/MoO 2 possesses superior bifunctional activities for HER and HzOR, requiring only −13 mV and −34.5 mV in 1 M KOH and 1 M KOH + 0.5 M N 2 H 4 , respectively, for achieving 10 mA cm−2. With Ru-MoNi/MoO 2 in a dual-electrode cell, only 0.57 V is needed to achieve 50 mA cm−2 with good stability, facilitating hydrazine-assisted OWS. [Display omitted] Improving the efficiency of overall water splitting (OWS) is crucial due to the slow four-electron transfer process in the oxygen evolution reaction (OER). The coupling of the thermodynamically favorable hydrazine oxidation reaction (HzOR) with the hydrogen evolution reaction (HER) significantly boosts hydrogen production. A Ru-decorated MoNi/MoO 2 micropillar (Ru-MoNi/MoO 2) has been synthesized using a hydrothermal followed by reduction annealing. Benefiting from Ru moderating the active interface of Mo-based alloys/oxides and the unique one-dimensional micropillar morphology. The synthesized Ru-MoNi/MoO 2 exhibits outstanding bifunctional activity for HER and HzOR, achieving 10 mA cm−2 at merely −13 mV and −34 mV in 1 M KOH and 1 M KOH + 0.5 M N 2 H 4 , respectively. Notably, with Ru-MoNi/MoO 2 in a dual-electrode setup, only 0.57 V is needed to achieve 50 mA cm−2, demonstrating good stability and facilitating hydrazine-assisted water splitting (OHzS). This work offers insights into the modulation of alloy/metal oxide active interfaces, contributing to the development of efficient bifunctional catalysts for HER and HzOR. [ABSTRACT FROM AUTHOR]

[Display omitted] • Mo, W doped Co 2 P/NF electrodes were designed for HER and GOR. • High catalytic efficiencies for HER, GOR were fulfilled. • The surface evolved CoO 2 was the genuine catalytic species for GOR. • H 2 and formate were coproduced by energy-saving glycerol electrolysis. H 2 and formate are important energy carriers in fuel-cells and feedstocks in chemical industry. The hydrogen evolution reaction (HER) coupling with electro-oxidative cleavage of thermodynamically favorable polyols is a promising way to coproduce H 2 and formate via electrochemical means, highly active catalysts for HER and electrooxidative cleavage of polycols are the key to achieve such a goal. Herein, molybdenum (Mo), tungsten (W) doped cobalt phosphides (Co 2 P) deposited onto nickel foam (NF) substrate, denoted as Mo-Co 2 P/NF and W-Co 2 P/NF, respectively, were investigated as catalytic electrodes for HER and electrochemical glycerol oxidation reaction (GOR) to yield H 2 and formate. The W-Co 2 P/NF electrode exhibited low overpotential (η) of 113 mV to attain a current density (J) of −100 mA cm−2 for HER, while the Mo-Co 2 P/NF electrode demonstrated high GOR efficiency for selective production of formate. In situ Raman and infrared spectroscopic characterizations revealed that the evolved CoO 2 from Co 2 P is the genuine catalytic sites for GOR. The asymmetric electrolyzer based on W-Co 2 P/NF cathode and Mo-Co 2 P/NF anode delivered a J = 100 mA cm−2 at 1.8 V voltage for glycerol electrolysis, which led to 18.2 % reduced electricity consumption relative to water electrolysis. This work highlights the potential of heteroelement doped phosphide in catalytic performances for HER and GOR, and opens up new avenue to coproduce more widespread commodity chemicals via gentle and sustainable electrocatalytic means. [ABSTRACT FROM AUTHOR]

This work proves that the Mo-doping is an efficient strategy for boosted NH 4 +-storage of VO 2 (B). Mo-doped VO 2 (B) delivers the specific capacitance of 1403 F g−1 (390 mAh g−1) at 0.1 A g−1. This strategy is like a Chinese idiom "like adding wings to a tiger" to guide the design of electrode materials for high-efficient NH 4 +-storage. [Display omitted] Supercapacitors (SCs) using ammonium-ion (NH 4 +) as the charge carrier (NH 4 +-SCs) have attracted continuous attention and vanadium-based materials are proved to have high-efficient NH 4 +-storage properties. Monoclinic vanadium dioxide, VO 2 (B), as an anode material applied to SCs has been rarely reported and modulating its electronic structure for boosted NH 4 +-storage is full of challenge. In this work, molybdenum-doped VO 2 (B) (Mo-doped VO 2 (B)) is designed and synthesize to enhance its NH 4 +-storage. The introduction of Mo atom into the crystal structure of VO 2 (B) can modulate its crystal structure and bring in some defects. Experimental results manifest that Mo-doped VO 2 (B) with 2 % Mo-doping shows the best electrochemical properties. Mo-doped VO 2 (B) achieves the specific capacitance of 1403 F g−1 (390 mAh g−1) at 0.1 A g−1 and the capacitance retention of about 98 % after 5000 cycle, superior to that of VO 2 (B) (893 F g−1, 248 mAh g−1 at 0.1 A g−1 and 60 % capacitance retention. The hybrid supercapacitor (HSC) assembled by Mo-doped VO 2 (B) and active carbon delivers good electrochemical performance with the energy density of 38.6 Wh kg−1 at power density of 208.3 W kg−1. This work proves that the Mo-doping is an efficient strategy for boosted NH 4 +-storage of VO 2 (B) and this strategy is like a Chinese idiom "like adding wings to a tiger" to guide the design of electrode materials for high-efficient NH 4 +-storage. [ABSTRACT FROM AUTHOR]

[Display omitted] • ·Mo 2 C-FeCu catalyst was designed by thermal reduction and carburization of precursor. • ·cinnamaldehyde/benzalacetone were synthesized at high yields and selectivities. • · α , β -unsaturated aldehyde/ketone were electrosynthesized in gentle and green manner. • ·C C coulping reaction was fulfilled by combined electrochemical-chemical pathway. Oxygen evolution reaction (OER) is the efficiency limiting half-reaction in water electrolysis for green hydrogen production due to the 4-electron multistep process with sluggish kinetics. The electrooxidation of thermodynamically more favorable organics accompanied by C C coupling is a promising way to synthesize value-added chemicals instead of OER. Efficient catalyst is of paramount importance to fulfill such a goal. Herein, a molybdenum iron carbide-copper hybrid (Mo 2 C-FeCu) was designed as anodic catalyst, which demonstrated decent OER catalytic capability with low overpotential of 238 mV at response current density of 10 mA cm−2 and fine stability. More importantly, the Mo 2 C-FeCu enabled electrooxidation assisted aldol condensation of phenylcarbinol with α -H containing alcohol/ketone in weak alkali electrolyte to selective synthesize cinnamaldehyde/benzalacetone at reduced potential. The hydroxyl and superoxide intermediate radicals generated at high potential are deemed to be responsible for the electrooxidation of phenylcarbinol and aldol condensation reactions to afford cinnamaldehyde/benzalacetone. The current work showcases an electrochemical-chemical combined C C coupling reaction to prepare organic chemicals, we believe more widespread organics can be synthesized by tailored electrochemical reactions. [ABSTRACT FROM AUTHOR]

[Display omitted] • Novel 1 T/2H-MoSe 2 /CN-TH dual-homojunction photocatalyst was designed for photocatalytic CO 2 reduction. • The intramolecular CN-TH homojunction could promote intralayer charge separation and migration. • The tandem multi-step charge transfer channel is achieved to accelerate the charge transfer dynamics. • The 1 T/2H-MoSe 2 /CN-TH exhibits a high CO yield of 27.36 μmol·g-1·h-1. Due to the high dissociation energy of carbon dioxide (CO 2) and sluggish charge transfer dynamics, photocatalytic CO 2 reduction with high performance remains a huge challenge. Herein, we report a novel dual-homojunction photocatalyst comprising of cyano/cyanamide groups co-modified carbon nitride (CN-TH) intramolecular homojunction and 1 T/2H-MoSe 2 homojunction (denoted as 1 T/2H-MoSe 2 /CN-TH) for enhanced photocatalytic CO 2 reduction. In this dual-homojunction photocatalyst, the intramolecular CN-TH homojunction could promote the intralayer charge separation and transfer owing to the strong electron-withdrawing capabilities of the two-type cyanamide, while the 1 T/2H-MoSe 2 homojunction mainly contributes to a promote interlayer charge transport of CN-TH. This could consequently induce a tandem multi-step charge transfer and accelerate the charge transfer dynamics, resulting in enhanced CO 2 reduction activities. Thanks to this tandem multi-step charge transfer, the optimized 1 T/2H-MoSe 2 /CN-TH dual-homojunction photocatalyst presented a high CO yield of 27.36 μmol·g−1·h−1, which is 3.58 and 2.87 times higher than those of 1 T/2H-MoSe 2 /CN and 2H-MoSe 2 /CN-TH single homojunctions, respectively. This work provides a novel strategy for efficient CO 2 reduction via achieving a tandem multi-step charge transfer through designing dual-homojunction photocatalyst. [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]

[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]

[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 dynamic evolution of Mo and Se during hydrogen evolution and their effects on the catalytic performance of HER were revealed by using interface engineering to construct MoSe 2 @CoSe 2 heterostructure. [Display omitted] Transition metal chalcogenides (TMCs) are recognized as highly efficient electrocatalysts and have wide applications in the field of hydrogen production by electrolysis of water, but the real catalytic substances and catalytic processes of these catalysts are not clear. The species evolution of Mo and Se during alkaline hydrogen evolution was investigated by constructing MoSe 2 @CoSe 2 heterostructure. The real-time evolution of Mo and Se in MoSe 2 @CoSe 2 was monitored using in situ Raman spectroscopy to determine the origin of the activity. Mo and Se in MoSe 2 @CoSe 2 were dissolved in the form of MoO 4 2- and SeO 3 2-, respectively, and subsequently re-adsorbed and polymerized on the electrode surface to form new species Mo 2 O 7 2- and SeO 4 2-. Theoretical calculations show that adsorption of Mo 2 O 7 2- and SeO 4 2- can significantly enhance the HER catalytic activity of Co(OH) 2. The addition of additional MoO 4 2- and SeO 3 2- to the electrolyte with Co(OH) 2 electrodes both enhances its HER activity and promotes its durability. This study helps to deepen our insight into mechanisms involved in the structural changes of catalyst surfaces and offers a logical basis for revealing the mechanism of the influence of species evolution on catalytic performance. [ABSTRACT FROM AUTHOR]

Integrated S-doped MoSe 2 nanosheets on hollow nanobox carbon fabricated via in situ growth and heterodoping strategy exhibits ultrahigh energy density and flexible characteristics in sodium ion pouch cell. [Display omitted] For the continued use of sodium-ion batteries (SIBs), which require matching anode materials, it is crucial to create high energy density energy storage devices. Here, hollow nanoboxes shaped carbon supported sulfur-doped MoSe 2 nanosheets (S-MoSe 2 @NC) are fabricated by in situ growth and heterodoping strategy. This ensures that the MoSe 2 nanosheets are tightly anchored to the nanoboxes carbon, and the structure can effectively buffer the volume stress caused by sodium ion (de)intercalation, as well as providing abundant ion/electron migration transportations. As anode for SIBs, the S-MoSe 2 @NC shows a higher rate capability and excellent cycling stability (431.1 mAh/g after 1100 cycles at 10 A/g). This excellent cycle life and high rate ability are due to the structural stability and outstanding electronic conductance with reduced band gap of the S-MoSe 2 @NC, as evidenced by the diffusion analysis and theoretical calculation. In order to promote the application of SIBs, the S-MoSe 2 @NC and NaNi 1/3 Fe 1/3 Mn 1/3 O 2 were assembled into a pouch cell, and the test found that besides the excellent cycle rate performance, the ultrahigh energy density of 256 Wh kg−1 and flexible characteristics can be achieved. This study has proven that building a structure with a rock-steady foundation and quick ion migration may efficiently control sodium storage and pave the way for novel applications of high-performance transition metal dichalcogenides in sodium storage. [ABSTRACT FROM AUTHOR]

Restricted growth of molybdenum carbide nanoparticles in hierarchically porous nitrogen-doped carbon matrix was prepared, which exhibits satisfactory electromagnetic wave absorption properties. This work enriches the variety of EMW absorbers and offers the route to promote the EMW absorption performance, especially large effective absorption bandwidth. [Display omitted] • MO 2 C/NC composites with honeycomb porous structure was synthesized; • This strategy enriches the variety of high-performance absorbers with mass production; • Bandwidth of 9.6 GHz at 3.5 mm was achieved for electromagnetic wave absorber; • Analysis of the absorption mechanism of MO 2 C/NC absorbers was investigated. With the development of electronic science and technology, electromagnetic pollution is becoming increasingly serious, which urgent people to develop wave-absorbing materials with the features of "thin, light, strong and wide". In this paper, restricted growth of molybdenum carbide nanoparticles in hierarchically porous nitrogen-doped carbon matrix (Mo 2 C/NC) was designed and prepared via a salt-assisted template route and carbonization process, whose morphology and the wave-absorbing properties are regulated by changing the content of Mo 2 C/NC nanoparticles. The honeycomb porous Mo 2 C/NC composites with large specific surface area and smooth surface can optimize the impedance matching and allow the entrance, multiple reflections and scattering of incident electromagnetic waves (EMW), which effective enhance the electromagnetic wave consumption. Meanwhile, the honeycomb cross-linked carbon matrix facilitates the construction of the conductive network and enhances its conductive loss. Furthermore, numerous Mo 2 C/NC nanoparticles dispersed restricted growth in carbon matrix induces interfacial polarization. In addition, the heteroatom nitrogen doping acts as dipole centers to induce dipole polarization under electromagnetic field. The uniquely designed Mo 2 C/NC absorbers show satisfactory EMW absorption behaviors of a minimum reflection loss (RL min) of −61.53 dB at 1.5 mm and an effective absorption bandwidth (EAB) of 9.6 GHz at 3.5 mm. This work enriches the variety of EMW absorbers and offers the route to promote the EMW absorption performance, especially large effective absorption bandwidth. [ABSTRACT FROM AUTHOR]

Nanosheets wrapped nanorods MoO 3 @MoCoP assembly was fabricated by facile solvothermal and thermally annealing, as well as phosphorization methods. XPS results proved the presence of oxygen vacancies and the changes in the electron structure of the catalyst. The oxygen vacancies can serve as ideal sites for water dissociation, optimizing the adsorption behavior and accelerating the Volmer reaction. Hence, the appropriate binding affinity of HER intermediates toward reduced energy barriers and an enhanced HER activity for MoO 3 @MoCoP. The enhanced HER activity of MoO 3 @MoCoP with efficient electron transport and optimal adsorption and desorption energy accounts for the activity close to that of commercially available Pt/C catalyst. [Display omitted] Regulating the electrocatalytic hydrogen evolution reaction (HER) performance through defect engineering of the surface of the catalysts is an effective pathway. Herein, cobalt-molybdenum phosphide (CoMoP) nanosheets wrapped molybdenum oxide (MoO 3) core–shell nanorods (MoO 3 @CoMoP), as alkaline electrocatalysts with ligand-derived N -doped carbon hybrid and oxygen-vacancies, were synthesized via solvothermal approaches and followed by phosphorization. As expected, the MoO 3 @MoCoP affords efficient HER with a low overpotential (η) of 84.2 ± 0.4 mV at 10 mA cm−2. After phosphorization, not only the MoCoP active species are incorporated into the catalyst, but also the defects sites are achieved. Impressively, the metal–ligand-derived MoCoP are distributed uniformly in the N -doped carbon hybrid matrix, exhibiting well-exposed active sites. Benefiting from the synergy effect of MoCoP active species and oxygen-vacancy, the MoO 3 @MoCoP showed increased conductivity and stability, which can deliver a current density of 10 mA cm−2 over 40 h. MoO 3 @MoCoP exhibits an optimal electronic structure on the surface by charge redistribution at the interface, thereby optimizing the hydrogen adsorption energy and accelerating the hydrogen evolution kinetics. This work paves the way for the design of transition metal electrocatalysts with desirable properties through a promising strategy in the field of energy conversion. [ABSTRACT FROM AUTHOR]

Klebsiella pneumoniae , a facultative anaerobe, relies on acquiring molybdenum to sustain growth in anaerobic conditions, a crucial factor for the pathogen to establish infections within host environments. Molybdenum plays a critical role in pathogenesis as it forms an essential component of cofactors for molybdoenzymes. K. pneumoniae utilizes the ABC (ATP-Binding-Cassette) transporter encoded by the modABC operon for uptake of the group VI elements molybdenum and tungsten. In this study, we determined the X-ray crystal structures of both the molybdenum-free and molybdenum-bound substrate-binding protein (SBP) ModA from Klebsiella pneumoniae to 2.00 Å and 1.77 Å resolution respectively. ModA crystallizes in the space group P222 with a single monomer in one asymmetric unit. The purified protein remained soluble and specifically bound molybdate and tungstate with K d values of 6.3 nM and 5.2 nM, respectively. Tungstate competes with molybdate by binding to ModA, resulting in enhanced antimicrobial activity. These data provide a starting point for structural and functional analyses of molybdate transport in K. pneumoniae. • We determined the 2.0 Å crystal structure of K. pneumoniae ModA. • A molybdate-bound structure reveals the residues required for binding molybdenum. • Molybdate and tungstate bind with similarly high affinity to ModA. • ModA is a potential target for therapeutic intervention using tungstate. [ABSTRACT FROM AUTHOR]

[Display omitted] • N doping and MoP heterostructures are achieved together through co-pyrolysis methods. • The heterostructures and doped N can synergistically optimize electronic structure. • MoP@ N -NiCoP requires low overpotentials of 43 mV and 232 mV to drive HER and OER. Transition metal phosphides (TMPs) are one of the most promising alternatives to noble metal electrocatalysts, but so far their activity and stability still fall short of expectations. Here, we prepare nitrogen-doped nickel–cobalt phosphide (N -NiCoP) and molybdenum phosphide (MoP) heterostructures engineered on nickel foam (NF) with nanosheet structure by high-temperature annealing and low-temperature phosphorylation. Notably, heteroatomic N doping and heterostructures construction are achieved together through a simple co-pyrolysis method. The distinctive composition can synergistically promote the electron transfer, lower the reaction barriers, thus improving the catalytic performance. Therefore, the modified MoP@ N -NiCoP requires low overpotentials of 43 mV and 232 mV to reach 10 mA cm−2 current density for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) accompanied by satisfactory stability in 1 M KOH. Density functional theory (DFT) calculations reveal the electron coupling and synergistic interfacial effects at the heterogeneous interface. This study provides a new strategy for heterogeneous electrocatalysts with elemental doping to promote hydrogen applications. [ABSTRACT FROM AUTHOR]

[Display omitted] • Stoichiometric amorphous MoOS 2 was prepared and tested in hydrogen evolution reaction (HER). • The structure of the oxysulfidic cluster was proposed based on EXAFS, Raman and DFT. • MoOS 2 possesses HER activity higher than MoS 2 , amorphous MoS 3 and a mixture of oxide and sulphide. • Oxygen has minor impact on the hydrogen desorption energy, dispersion and textural properties being more important factors. Amorphous molybdenum oxysulfide MoOS 2 obtained by acidification of aqueous MoO 2 S 2 2− solutions was structurally characterized and tested as a catalyst for hydrogen evolution reaction (HER). Raman, XPS and XAS characterizations show that the solid contains oligomers based on the Mo(V) core Mo 2 O 2 S 4 units, exposing dangling Mo O bonds and connected via Mo-S-Mo bridges. MoOS 2 demonstrated higher HER activity than reference catalysts including nanocrystalline MoS 2 , amorphous MoS 3 and MoS 2 /MoO 2 composite obtained by thermal decomposition of MoOS 2. DFT calculations suggest that introduction of oxygen adjacent to the disulfide bridges in the molybdenum coordination does not change significantly the free energy of hydrogen desorption, as compared with fully sulfided Mo x S y clusters. Higher HER catalytic activity of the MoOS 2 material was explained by abundance of disulfide S 2 2− moieties able to dissociate hydrogen and by fine dispersion of the material. [ABSTRACT FROM AUTHOR]

[Display omitted] • On methane dearomatization reaction, two main deactivation modes occurs. • Irreversible damage by zeolite amorphization during the isothermal pre-treatment. • Reversible deactivation by coke deposition ("soft", "hard" and carbide species). • 3 descriptors : coke level, micropore volume loss, monoclinic/orthorhombic change. We report a detailed kinetic study of methane dehydroaromatization on three bifunctional Mo/HZSM-5 catalysts (0.9 wt%, 2.7 wt%, and 17.2 wt% Mo). Two main deactivation modes are present: (i) irreversible damage by zeolite amorphization during the isothermal pre-treatment in an inert atmosphere and (ii) reversible deactivation by coke deposition ("soft", "hard" and carbide species). The former occurs at high Mo loading (>4.0 w%) and provides low activity catalysts. Catalysts with a lower and well-balanced molybdenum loading (<4 w%) suffer mainly from the second deactivation mode. The catalyst decay is modelled by semi-empirical laws including time on stream and coke level. The latter initiates textural and structural catalyst modifications leading to an activity loss. Three deactivation descriptors, 1 : coke level on the spent samples, 2: loss of micropore volume, and 3: monoclinic/orthorhombic phase transition of the zeolite are identified. Further characterization indicates that both molybdenum and carbon species are responsible for the catalytic deactivation of well-balanced catalysts. At least 50% of the initially dispersed molybdenum migrates to the external surface of the zeolite to form large clusters of molybdenum carbide. The coke extracted from the zeolite micropores are confirmed to be mainly unsubstituted polyaromatics. [ABSTRACT FROM AUTHOR]

The presence of VO 3 - promotes the transformation from the α -MoO 3 to the h -MoO 3. Compared to conventional α -MoO 3 and h -MoO 3 , the insertion of VO 3 - helps to improve the zinc storage performance. [Display omitted] Molybdenum trioxide (MoO 3) has been widely studied in the energy storage field due to its various phase states and unique structural advantages. Among them, lamellar α -phase MoO 3 (α -MoO 3) and tunnel-like h -phase MoO 3 (h- MoO 3) have attracted much attention. In this study, we demonstrate that vanadate ion (VO 3 -) can transform α -MoO 3 (a thermodynamically stable phase) to h -MoO 3 (a metastable phase) by altering the connection of [MoO 6 ] octahedra configurations. h -MoO 3 with VO 3 - inserted (referred to as h -MoO 3 -V) as the cathode material for aqueous zinc ion batteries (AZIBs) exhibits excellent Zn2+ storage performances. The improvement in electrochemical properties is attributed to the open tunneling structure of the h -MoO 3 -V, which offers more active sites for Zn2+ (de)intercalation and diffusion. As expected, the Zn// h -MoO 3 -V battery delivers specific capacity of 250 mAh·g−1 at 0.1 A·g−1 and rate capability (73% retention from 0.1 to 1 A·g−1, 80 cycles), well exceeding those of Zn// h -MoO 3 and Zn// α -MoO 3 batteries. This study demonstrates that the tunneling structure of h -MoO 3 can be modulated by VO 3 - to enhance the electrochemical properties for AZIBs. Furthermore, it provides valuable insights for the synthesis, development and future applications of h -MoO 3. [ABSTRACT FROM AUTHOR]

[Display omitted] • A fascinating 3D Mo-NiCoP/NF honeycomb electrocatalyst was synthesized using polystyrene as the template. • The bifunctional 3D Mo-NiCoP/NF electrode showed superior electrocatalytic performance. • The appearance, structure and electrocatalytic mechanisms of 3D Mo-NiCoP/NF were explored in detail. • The efficiency of alkaline decoupled water splitting reach to be 95% at 10 mA/cm2. Two-step alkaline water electrolysis is considered a safe and efficient method for producing hydrogen from renewable energy. Reversal of the current polarity in a bifunctional electrocatalyst used as a gas evolution electrode (GEE) in two-step water electrolysis can generate H 2 /O 2 at different times and in different spaces. The design of a bifunctional electrocatalyst with high durability and excellent activity is imperative to achieving continuous, safe, and pure H 2 generation via two-step alkaline water electrolysis. Here, we present for the first time a novel 3D Mo-doped NiCo phosphide honeycomb electrocatalyst that was grown on nickel foam (3D Mo-NiCoP/NF) and fabricated using polystyrene as a template. The electrocatalyst exhibited extremely low overpotentials in both the hydrogen evolution reaction (HER; 117 mV at 10 mA/cm2) and the oxygen evolution reaction (OER; 344 mV at 100 mA/cm2). As a bifunctional electrocatalyst for two-step alkaline water electrolysis, the device had a 1.784 V cell voltage at 10 mA/cm2, 95% decoupling efficiency, and ∼83% energy conversion efficiency. Taken together, the use of 3D Mo-NiCoP/NF as a GEE reduced the complexity and lowered the cost of the electrolyzer. The latter could be used to construct highly competitive water-splitting systems for continuous H 2 production and green energy harvesting. [ABSTRACT FROM AUTHOR]

Commercial NiMo foam processed by salt-baking 'recipe' gained a giant leap in electrocatalytic activity. [Display omitted] Ni-based metal foam holds promise as an electrochemical water-splitting catalyst, due to its low cost, acceptable catalytic activity and superior stability. However, its catalytic activity must be improved before it can be used as an energy-saving catalyst. Here, a traditional Chinese recipe, salt-baking, was employed to surface engineering of nickel-molybdenum alloy (NiMo) foam. During salt-baking, a thin layer of FeOOH nano-flowers was assembled on the NiMo foam surface then the resultant NiMo-Fe catalytic material was evaluated for its ability to support oxygen evolution reaction (OER) activity. The NiMo-Fe foam catalyst generated an electric current density of 100 mA cm−2 that required an overpotential of only 280 mV, thus demonstrating that its performance far exceeded that of the benchmark catalyst RuO 2 (375 mV). When employed as both the anode and cathode for use in alkaline water electrolysis, the NiMo-Fe foam generated a current density (j) output that was 3.5 times greater than that of NiMo. Thus, our proposed salt-baking method is a promising simple and environmentally friendly approach for surface engineering of metal foam for designing catalysts. [ABSTRACT FROM AUTHOR]

A 3D interconnected MoS 2 /MWCNTs framework with the significantly expanded interlayer spacing of 1.05 nm is designed through a novel strategy of vacuum evacuation followed by hydrothermal method. Benefitting from the confined structural configuration, sufficient active surface and 3D structural stability, as-prepared MoS 2 /MWCNTs cathode shows superior electrochemical properties for aqueous ZIBs. [Display omitted] • The 3D interconnected MoS 2 /MWCNTs was prepared by a simple method. • MoS 2 /MWCNTs materials show the (0 0 2) enlarged interlayer spacing of 1.05 nm. • Synergistic effect of 3D and confined structure design shows superior properties. • The cathode shows excellent cycling stability and rate capability. Layered molybdenum disulfide (MoS 2) shows tremendous prospect as cathode material for aqueous zinc-ion batteries (AZIBs) due to the two-dimensional zinc ions (Zn2+) diffusion channels and tunable interlayer spacing. However, it is subjected to sluggish insertion/extraction kinetics, inferior electronic conductivity and inadequate active capacities. Herein, a three-dimensional (3D) interconnected MoS 2 /multi-walled carbon nanotubes (MWCNTs) framework is proposed to address these issues. Importantly, the MWCNTs cores offer interconnection routes for fast electrons and zinc ions transport, the expanded spacing of MoS 2 interlayer with 1.05 nm can facilitate rapid Zn2+ intercalation/extraction, and the confined MoS 2 layers in inner MWCNTs can mitigate the agglomeration and restacking of MoS 2 nanosheets. Benefitting from the confined structural configuration, sufficient active surface and 3D structural stability, the MoS 2 /MWCNTs as AZIBs cathode delivers a large initial reversible capacity of 218.3 mAh/g and high coulombic efficiency of 78.2 % at 0.1 A/g. Additionally, the 3D interconnected cathode maintains nearly intact structure after a fierce galvanostatic charge/discharge process, resulting in large retained capacities of 126.3 mAh/g at 1 A/g after 650 cycles and 101.1 mAh/g at 3 A/g after 1000 cycles. This work offers a novel strategy for the structure design of two-dimensional materials to develop high-performance cathodes for AZIBs. [ABSTRACT FROM AUTHOR]

The as-prepared Ni-MoN-450 (pyrolysis at 450 °C) displays good hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) performances in alkaline media. Moreover, it also exhibits low voltage for overall water-splitting with excellent stability under large-current density. [Display omitted] • The graphene-like two-dimensional morphology with highly exposed active sites determines the electrocatalytic activity and selectivity. • Ni-MoN-450 acts as efficient electrocatalyst under an industrial environment. • The catalyst depicts exceptional performance in all the three reactions of OER, HER and overall water splitting. Transition metal nitride (TMNs) electrocatalysts have attracted tremendous attentions for their unique electron structure, high activity, and excellent stability. Herein, a two-dimensional (2D) graphene-like structured nickel-molybdenum nitride (Ni-MoN) on nickel foam (NF), is prepared via facile hydrothermal and following nitridation process. The as-prepared Ni-MoN-450 (pyrolysis at 450 °C) displays good hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) performances in alkaline media. Only 22 mV and 117 mV are needed to achieve current densities of 10 mA cm−2 and 500 mA cm−2 in 1.0 M KOH, respectively, toward HER. The assembled two-electrode system, with the synthesized Ni-MoN-450 as the anode and cathode, exhibits good performance to achieve 1000 mA cm−2 in 1.0 M KOH + 25 °C and 6.0 M KOH + 80 °C. Moreover, it also presents long-term stability under large-current density, which verified its robust property. [ABSTRACT FROM AUTHOR]

[Display omitted] • This study realizes rational construction of the hierarchical wing-like iron/molybdenum oxide heterojunction on nickel foam (FMO/NF). • Hierarchical porous structure composed of the nanoparticle-micron sheets facilitates electrolyte/catalyst contact and bubble release. • The synergistic effect of Fe and Mo combined with the interfacial effect of the heterojunction optimizing structural configurations. • FMO/NF exhibits distinguished performance for overall water splitting in alkaline solution. Designing heterojunction catalysts with high-energy interfacial effects, especially combining the geometrical advantages of hierarchical micro-nano structures with the advantages of bi- or multi-metal syergistically optimised electronic coordination environments, is crucial for achieving efficient and stable water splitting. In this study, a simple one-step hydrothermal method was used to construct a hierarchical wing-like iron/molybdenum oxide heterojunction with a porous structure on nickel foam (FMO/NF). The synergistic effect of Fe, Mo, and the heterostructures can enrich structural defects, overcome the disadvantages of the individual components, and improve material performance by optimising the structural configurations and electronic properties and exploiting the electronic interactions that occur between interfaces composed of different phases. In addition, owing to the high porosity of the hierarchical micro-nano structure and abundant active sites, the wing-like FMO/NF was utilised as an efficient bifunctional catalyst for the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER), presenting low overpotentials of 278.06 and 263.72 mV, respectively, at a current density of 100 mA·cm−2 in 1 mol/L KOH. Furthermore, assembling FMO/NF as both the anode and cathode (FMO/NF || FMO/NF) required a cell voltage of 1.87 V to drive 100 mA·cm−2 in 1 mol/L KOH, and it proceeded continuously for 110 h with negligible cell voltage decay. This work provides a rational synthetic route for the preparation of innovative double transition metal-based micro-nano hierarchical heterostructured electrocatalysts with a synergistic effect and further advances the development of energy-conversion technology. [ABSTRACT FROM AUTHOR]

Self-assembled cobalt-molybdenum layered double hydroxide hierarchical microtubes are synthesized based on a structural engineering and electronic state tuning, it has excellent performance for OER. [Display omitted] • Mo-doped cobalt hydroxide nanosheet hierarchical microtubules are fabricated using MoO 3 nanorods as sacrificial templates. • X-ray-based spectroscopic tests reveal that Mo (VI) with tetrahedral coordination intercalate into the interlayer of cobalt hydroxide. • Under alkaline condition, the OER overpotential is 288 mV at a current density of 10 mA cm−2. Cobalt-based hydroxide are ideal candidates for the oxygen evolution reaction. Herein, we use molybdenum oxide nanorods as sacrificial templates to construct a self-supporting molybdenum-doped cobalt hydroxide nanosheet hierarchical microtubule structure based on a structural engineering strategy to improve the active area of the catalyst. X-ray-based spectroscopic tests revealed that Mo (VI) with tetrahedral coordination intercalated into the interlayer of cobalt hydroxide, promoting interlayer separation. At the same time, Mo is connected with Co through oxygen bonds, which promotes the transfer of Co charges to Mo and reduces the electron cloud density of Co ions. In 1 M KOH, optimized molybdenum-doped cobalt hydroxide nanosheet microtubules only needs an overpotential of 288 mV to drive a current density of 10 mA cm−2, which is significantly better than that of pure Co(OH) 2 nanosheets and RuO 2. Structural engineering and electronic state regulation can effectively improve the oxygen evolution activity of cobalt-based hydroxide, which provides a design idea for the development of efficient oxygen evolution catalysts. [ABSTRACT FROM AUTHOR]

A novel kind of hybrid electrode is successfully developed by introducing trace Ir species onto a hierarchical Ni/Mo 5 N 6 heterostructure on Ni foam, presenting as a highly-active bifunctional electrocatalyst for AEM water electrolyzer. [Display omitted] Developing highly active electrocatalysts is a pivotal issue for anion-exchange membrane water electrolyzers (AEMWE). However, realizing the continuous hydrogen generation at a large current density remains challenging. Herein, a novel kind of hybrid electrode is successfully developed by introducing trace iridium (Ir) species onto a hierarchical Ni/Mo 5 N 6 heterostructure on Ni foam (Ir-Ni/Mo 5 N 6 /NF). The synergistic advantages of high conductivity, abundant active sites, and strong electronic interaction endow superior reaction kinetics, presenting a highly-active bifunctional electrocatalyst. Remarkably, the Ir-Ni/Mo 5 N 6 /NF exhibit extremely low overpotentials of 52 mV and 250 mV at 100 mA cm−2 for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). By exploiting the Ir-Ni/Mo 5 N 6 as both anode/cathode, the constructed AEMWE device delivers superior performance. The current density reaches 2.1 A cm−2 at a voltage of 2.0 V and 250 mA cm−2 at 1.8 V in alkaline/neutral media. This work put forward a facile and effective strategy to synthesize advanced bifunctional electrocatalysts for water electrolysis. [ABSTRACT FROM AUTHOR]

[Display omitted] • Development of a fluorine-free hydrothermal method for the preparation of MoS 2 /Mo 2 CT x MXene. • Thioacetamide was used as the source of sulfide ions for the sulfidation of MXene. • Microwave-assisted hydrothermal treatment resulted in MoS 2 formation on the MXene surface. • Amorphous MoS 2 on the MXene surface enhanced its chemical stability. • MoS 2 /Mo 2 CT x exhibited superior catalytic activity for the hydrogen evolution reaction in alkaline medium. Synthesizing MXenes from M n+1 AX n (MAX) phases using hazardous hydrogen fluoride is a common and effective method. However, fluorine termination on the basal planes and edges of the resulting MXenes is undesirable for the electrocatalytic hydrogen evolution reaction (HER), while oxygen (O), hydroxyl (OH), and sulfur (S) termination favors this reaction. Herein, we unveil a simple fluorine-free exfoliation and two-step vulcanization method for synthesizing molybdenum sulfide-modified molybdenum carbide (MoS 2 /Mo 2 CT x MXene, T = OH, O, S) for the HER in alkaline medium. Microwave-assisted hydrothermal treatment of the MAX phase (Mo 3 AlC 2) with sodium hydroxide-sodium sulfide as an etching solution and thioacetamide as a source of sulfide ions enabled the selective dissolution of the aluminum (Al) layer and sulfidation of the surface Mo atoms to form amorphous MoS 2. Thus, the vulcanization of Mo 2 CT x MXene resulted in the formation of MoS 2 /Mo 2 CT x MXene. The MoS 2 formed on the surface of Mo 2 CT x provided enhanced stability by preventing oxidation. MoS 2 /Mo 2 CT x exhibited enhanced electrocatalytic activity toward the HER, mainly due to the O, OH, and amorphous MoS 2 functionalities. The MoS 2 sites on the surface exhibited an overpotential of 110 ± 7 mV at a current density of 10 mA cm−2 as a result of enhanced charge transfer and mass transfer. Thus, the sulfidation method demonstrated herein is capable of producing amorphous MoS 2 structures on Mo 2 CT x MXene, which could be applied for the surface modification of other molybdenum-based nanomaterials or electrocatalysts to improve stability and enhance electrocatalytic activity. [ABSTRACT FROM AUTHOR]

Co-MoP/PCNFs modified Celgard separator in Lithium-sulfur battery. [Display omitted] Rational design of separators is especially critical to solve the "shuttle effect" of lithium polysulfides (LiPSs) and the sluggish redox kinetics in lithium-sulfur batteries (LSBs). Here, the multi-functional nanocomposite involving Co-doped molybdenum phosphide (Co-MoP) nanofibers and porous carbon nanofibers (PCNFs) is designed and prepared through electro-blow spinning and phosphating process, which possesses multiple adsorption and catalytic sites and is acted as the functional material for LSBs separators. In this multifunctional nanocomposite, the prepared Co-MoP nanofibers can provide internal adsorption and catalytic sites for LiPSs conversion. And the interconnected nitrogen-doped PCNFs can be elaborated an efficient LiPSs mediator and accommodate the huge volume changes in the reaction process for LSBs. Benefiting from the multiple adsorptive and catalytic sites of the developed functional materials, the assembled LSBs with a Co-MoP/PCNFs modified separator display outstanding electrochemical performances, including an admirable capacity retention of 770.4 mAh g−1 after 400 cycles at 1.0 C, only 0.08 % capacity decay per cycle at 2.0 C, rate performance up to 5 C, and also decent areal capacity even under a high sulfur loading of 4.9 mg cm−2. The work provides a facile pathway towards multifunctional separators in LSBs, and it may also help deepen preparation method of MoP through the electrostatic blowing/electrospinning technology in other related energy storage fields. [ABSTRACT FROM AUTHOR]

[Display omitted] As a kind of high-performance and cost-efficient electrocatalyst in water splitting, the transition bimetal phosphides exhibit a promising prospect. Here, the composite of cobalt molybdenum phosphide nanoparticles embedded in crosslinked nitrogen-doped carbon nanofiber (Co 0.4 Mo 0.6 P@CL-NCNF) has been synthesized via an electrospinning process and pyrolysis treatment. As an effective hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) catalyst, the Co 0.4 Mo 0.6 P@CL-NCNF only requires the overpotentials of 81 mV and 219 mV at the current densities of 10 mA cm−2 and 20 mA cm−2, respectively. Moreover, the water electrolyzer with the Co 0.4 Mo 0.6 P@CL-NCNF as the cathode and anode catalysts requires a cell voltage of 1.59 V to reach a current density of 10 mA cm−2. The Co 0.4 Mo 0.6 P@CL-NCNF also achieves the excellent stability up to 24 h for HER, OER and overall water spitting in 1.0 M KOH. The excellent catalytic activity of the Co 0.4 Mo 0.6 P@CL-NCNF is benefits from the synergistic effect between components and the crosslinked structure of carbon nanofiber. Thus, the research provides a promising method for preparing carbon-based TMPs materials towards electrocatalysis. [ABSTRACT FROM AUTHOR]

Isotope technology is an ideal tool for tracing the sources of certain pollutants or providing insights into environmental processes. In recent years, the advent of multi-collector inductively coupled plasma mass spectrometry (MC-ICP-MS) has enabled the precise measurement of various metal stable isotopes. Due to the presence of "fingerprint" properties in various environmental samples, metal stable isotopes have been applied to distinguish the source of contaminants effectively and further understand the corresponding environmental processes. The environmental fate of metal elements is strongly controlled by adsorption, an essential process for the distribution of elements between the dissolved and particulate phases. The adsorption of metal elements on mineral and organic surfaces significantly affects their biogeochemical cycles in the environment. Therefore, it is crucial to elucidate the fractionation characteristics of stable metal isotopes during the adsorption process. In this review, three typical transitional metal elements were selected, considering Mo as the representative of anionic species and Fe and Zn as the representative of cationic species. For Mo, the heavier Mo isotope is preferentially adsorbed in the solution phase, pH has a more significant influence on isotope fractionation, and temperature and ionic strength are relatively insensitive. Differences in coordination environments between dissolved and adsorbed Mo during adsorption, i.e., attachment mode (inner- or outer-sphere) or molecular symmetry (e.g., coordination number and magnitude of distortion), are likely responsible for isotopic fractionation. For Fe, The study of equilibrium/kinetic Fe isotopic fractionation in aqueous Fe(II)-mineral is not simple. The interaction between aqueous Fe(II) and Fe (hydroxyl) oxides is complex and dynamic. The isotope effect is due to coupled electron and atom exchange between adsorbed Fe(II), aqueous Fe(II), and reactive Fe(III) on the surface of Fe (hydroxyl) oxide. For Zn, the heavier Fe isotope preferentially adsorbs on the solid phase, and pH and ionic strength are essential influencing factors. The difference in coordination environment may be the cause of isotope fractionation. [Display omitted] • The analytical techniques of Mo, Fe, and Zn stable isotopes were systematically summarized. • The characteristics and mechanism of Mo, Fe, and Zn stable isotopes fractionation during adsorption process were elaborated. • The prospects for future research issues related to stable metal isotopes were provided. [ABSTRACT FROM AUTHOR]

Two polymorphic Ni–Mo-based coordination polymers (CPs) based on the ligand N , N ′-bis(4-pyridinecarboxamide)-1,2-cyclohexane (4-bpah) were created using hydrothermal synthesis. Each of these CPs (denoted as Ni–Mo-1 and Ni–Mo-2) has the similar main framework [Ni(4-bpah) 2 (Mo 2 O 7)], but they each show different crystalline phases with different 2D grid windows. Moreover, the Ni–Mo-based CP-derived carbon-based composites (C–Ni–Mo-X-Y , X = 1 or 2 and Y = 400, 450, or 500) were prepared by thermal cracking and "low-temperature" calcination below 500 °C using two CPs as precursors. The results show that the Ni–Mo-based CP-derived carbon-based composites prepared at different temperatures exhibit irregular morphologies with different micron-sized or nano-sized loose structures and chemical compositions. Furthermore, the dye and gas iodine adsorption properties of the C–Ni–Mo-X-Y composites were investigated in detail. Two novel two-dimensional polycrystalline nickel-molybdenum based coordination polymers have been designed and synthesized as carbon-based composites by a facile method. Their gas iodine adsorption/release and dye adsorption capacities were studied in detail. [Display omitted] • Two polymorphic Ni–Mo-based CPs were created using hydrothermal synthesis. • Bimetallic-doped materials derived from Ni–Mo-CPs were prepared under low temperature. • Derived materials exhibited micron- or nano-sized structures and chemical compositions. • C–Ni–Mo-2-450 was found to be able to efficiently remove gaseous iodine from air. • C–Ni–Mo-2-450 exhibited stable dye adsorption performance even after five cycles. [ABSTRACT FROM AUTHOR]

Considering the significant impact of potentially toxic elements (PTEs) on the ecosystem and human health, this paper, investigated the contamination level of four PTEs (Zn, Cu, Mo and Pb) and their mobility in sediments of Mahabad dam and river. Choosing the most effective machine learning algorithms is very important in accurately predicting bioavailability of PTEs. Therefore, four machine learning (ML) models including decision tree regression (DTR), random forest regression (RFR), multi-layer perceptron regression (MLPR) and support vector regression (SVR), were used and compared for estimating the selected PTEs bioavailability. For these models, 9 variables (total concentration, pH, EC, OM and five chemical forms F1 to F5 obtained by sequential extraction) in 100 sediment samples were considered. The results showed that contamination level decreases from Zn and Cu to Pb and Mo, but the order of the mobility coefficient of the elements in the sediment follows the trend of zinc > copper > molybdenum > lead, and variation coefficient indicated more variability of spatial distribution for Zn and Cu. Among the four tested models, DTR and RFR performed the best for predicting PTEs bioavailability variations (with roc_auc>0.9, R2 > 0.8 and MSE>0.5), followed by MLPR and SVR. Furthermore, the relevance of the factors controlling the metals availability, evaluated using the RFR-based feature importance method and Pearson correlation, revealed that the most important physicochemical property for Zn, Cu and Mo bioavailability was pH, whereas for Pb, EC was the determinant factor. In the case of chemical speciation, F5 had an inverse correlation with the target, while F1 and F2 had a direct correlation. These fractions contributed significantly to the prediction results. This study represents the potential successful application of ML to PTEs risk control in sediments and early warning for the surrounding water PTEs contamination. [Display omitted] • The highest PTEs concentrations were observed downstream of the wastewater treatment and petrochemical plants. • Zn is the most bioavailable element in sediment samples. • PH is the most important physicochemical parameter influencing PTEs bioavailability. • DTR and RFR demonstrated better fitting performance in predicting PTEs availability. [ABSTRACT FROM AUTHOR]

Primary producers are essential organisms for marine ecosystems because they form the basis of food webs, produce half of atmospheric oxygen and are involved in various biogeochemical cycles. At the end of a bloom event, phytoplankton cells are known to produce organic compounds that act as a 'cement', allowing the cells to stick together and form large sinking structures called aggregates. These aggregates are microenvironments with chemical properties that are very different from the surrounding water. The main objective of this study was to determine how the temporal variations in cell assemblages over time and the formation of aggregates following a bloom affect the concentrations of molybdenum (Mo) and barium (Ba) in the water column, which are elements typically measured within accretionary hard tissues (e.g., mollusc shells) to track phytoplankton dynamics in the environment. To do so, we performed an environmental monitoring from March to October 2021 at Lanvéoc in the Bay of Brest (France) during which several biological (e.g., variations in phytoplankton assemblages) and chemical (e.g., chemical properties of the water column) parameters were measured once to twice per week. Our results show that spring and summer blooms of Gymnodinium , known to be enriched in Mo, could be one of the reasons explaining the particulate Mo enrichments in the water column. In addition, large phytoplankton aggregates transported a significant amount of Mo to the seafloor and associated suspension feeders. In contrast, the temporal variations in dissolved and particulate Ba concentration were strongly influenced by the formation of diatom blooms. Interestingly, there was a significant shift in Ba from the dissolved to the particulate fraction during the largest diatom bloom in late spring, associated with a significant Ba transport to the seafloor, which may be explained by the adsorption of this element onto diatom frustules. This study therefore highlights the impacts of phytoplankton on the dynamics of these elements in coastal ecosystems. [ABSTRACT FROM AUTHOR]

Biological characteristics of pregnant women during early pregnancy make them susceptible to both poor sleep quality and metal/metalloid exposure. However, the effects of metal(loid) exposure on sleep quality in pregnant women remain unknown and unexplored. We aimed to examine the relationship between exposure to a mixture of metal(loid)s and pregnant women's sleep quality during early pregnancy. We recruited 493 pregnant women in the first trimester from prenatal clinics in Jinan, Shandong Province, China, and collected their spot urine samples. All urine specimens were assessed for eight metal(loid)s: arsenic (As), cadmium (Cd), iron (Fe), zinc (Zn), molybdenum (Mo), lead (Pb), selenium (Se), and mercury (Hg). We used the Pittsburgh Sleep Quality Index (PSQI) to assess sleep quality. Linear regression, logistic regression, generalized additive models (GAMs), quantile g-computation, and Bayesian kernel machine regression (BKMR) were applied to investigate the relationships between metal(loid) exposure and sleep quality. The results from single metal(loid) models, quantile g-computation models, and BKMR models consistently suggested that Fe was positively related to women's sleep quality. Moreover, in the quantile g-computation models, As was the most critical contributor to the negative effects of the metal(loid) mixture on sleep quality. In addition, we found significant As by Fe interaction for scores of PSQI and habitual sleep efficiency, Pb by Fe interaction for PSQI and sleep latency, and Hg by Fe interaction for PSQI, suggesting the interactive effects of As and Fe, Pb and Fe, Hg and Fe on sleep quality and specific sleep components. Our study provided the first-hand evidence of the effects of metal(loid) exposure on pregnant women's sleep quality. The underlying mechanisms need to be explored in the future. • Exposure to Fe and As was associated with the sleep quality of pregnant women. • Interactive effects of As and Fe on sleep quality of pregnant women were found. • Pb by Fe and Hg by Fe interactions were found for sleep quality of pregnant women. [ABSTRACT FROM AUTHOR]

There is a noticeable lack of information on the levels of both non-essential and essential trace elements in women aged over 50. The main objective of this study is to investigate trace element concentrations and explore the influence of sociodemographic factors and dietary sources of exposure in this demographic. We analyzed 19 trace elements, including manganese, cobalt, copper, zinc, molybdenum, chromium, nickel, arsenic, strontium, cadmium, tin, antimony, cesium, barium, tungsten, mercury, thallium, lead, and uranium, using ICP-MS and mercury analyzer. Urine samples were obtained from a cohort of 851 women aged over 50 who participated in the 8th KoGES-Ansung study (2017–2018). Multiple linear models were employed to explore associations between urinary trace element concentrations and sociodemographic factors and dietary sources of exposure. We used K-means clustering to discern patterns of exposure to trace elements and identify contributing factors and sources. Our findings indicate higher concentrations of molybdenum (Mo), arsenic (As), cadmium (Cd), and lead (Pb) in our study population compared to women in previous studies. The study population were clustered into two distinct groups, characterized by lower or higher urinary concentrations. Significant correlations between age and urinary concentrations were observed in Ni. Smoking exhibited positive associations with urinary Cd and As. Associations with dietary sources of trace elements were more distinct in women in the high-exposure group. Urinary antimony (Sb) was positively linked to mushroom and egg intake, As to mushroom and fish, and Hg to egg, dairy products, fish, seaweed, and shellfish. Our study underscores the significant gap in understanding urinary concentrations of trace elements in women aged over 50. With higher concentrations of certain elements compared to previous studies and significant correlations between age, smoking, and specific food sources, it is imperative to address this gap through targeted dietary source-specific risk management. [Display omitted] • In women aged over 50, 19 trace elements were analyzed, revealing elevated urinary concentrations of Mo, As, Cd, and Pb. • The study population exhibited clear clustering into two groups with distinct patterns of trace element concentrations. • Age correlated with Mo and Ni, while smoking showed positive associations with Cd and As. • Dietary sources were more pronounced in women with higher exposures, linking urinary Hg, As, and Sb to specific foods. [ABSTRACT FROM AUTHOR]

Several studies have suggested an association between exposure to various metals and the onset of type 2 diabetes (T2D). However, the results vary across different studies. We aimed to investigate the associations between serum metal concentrations and the risk of developing T2D among 8734 participants using a prospective cohort study design. We utilized inductively coupled plasma mass spectrometry (ICP-MS) to assess the serum concentrations of 27 metals. Cox regression was applied to calculate the hazard ratios (HRs) for the associations between serum metal concentrations on the risk of developing T2D. Additionally, 196 incident T2D cases and 208 healthy control participants were randomly selected for serum metabolite measurement using an untargeted metabolomics approach to evaluate the mediating role of serum metabolite in the relationship between serum metal concentrations and the risk of developing T2D with a nested case control study design. In the cohort study, after Bonferroni correction, the serum concentrations of zinc (Zn), mercury (Hg), and thallium (Tl) were positively associated with the risk of developing T2D, whereas the serum concentrations of manganese (Mn), molybdenum (Mo), barium (Ba), lutetium (Lu), and lead (Pb) were negatively associated with the risk of developing T2D. After adding these eight metals, the predictive ability increased significantly compared with that of the traditional clinical model (AUC: 0.791 vs. 0.772, P =8.85×10−5). In the nested case control study, a machine learning analysis revealed that the serum concentrations of 14 out of 1579 detected metabolites were associated with the risk of developing T2D. According to generalized linear regression models, 7 of these metabolites were significantly associated with the serum concentrations of the identified metals. The mediation analysis showed that two metabolites (2-methyl-1,2-dihydrophthalazin-1-one and mestranol) mediated 46.81% and 58.70%, respectively, of the association between the serum Pb concentration and the risk of developing T2D. Our study suggested that serum Mn, Zn, Mo, Ba, Lu, Hg, Tl, and Pb were associated with T2D risk. Two metabolites mediated the associations between the serum Pb concentration and the risk of developing T2D. • Association between metals and type 2 diabetes (T2D) remain inconsistent. • Cohort study and mediation analysis was used to uncover link between metals and T2D. • Level of 8 metals were identified to be associated with incident T2D risk. • 2 metabolites mediated 46.81% and 58.70% of the association between Pb and T2D risk. [ABSTRACT FROM AUTHOR]

A template-engaged multistep synthesis process is developed to fabricate ultrathin carbon nanosheets assembled hierarchical nanoboxes embedded with dense Mo-N 4 active sites, which exhibited excellent activity and superb stability for oxygen reduction reaction. [Display omitted] • Unique hierarchical SA-Mo-C nanoboxes were fabricated via a template-engaged multistep synthesis process. • Comprehensive characterizations including EXAFS reveal Mo-N 4 atomic sites were formed and densely dispersed in the SA-Mo-C nanoboxes. • SA-Mo-C nanoboxes exhibited better ORR performance compared to commercial Pt/C catalysts. Construction of single-atom catalysts (SACs) with maximally exposed active sites remains a challenging task mainly because of the lack of suitable host matrices. In this study, hierarchical N -doped carbon nanoboxes composed of ultrathin nanosheets with dispersed atomic Mo (denoted as hierarchical SA-Mo-C nanoboxes) were fabricated via a template-engaged multistep synthesis process. Comprehensive characterizations, including X-ray absorption fine structure analysis, reveal the formation of Mo-N 4 atomic sites uniformly anchored on the hierarchical carbon nanoboxes. The prepared catalysts offer structural and morphological advantages, including ultrathin nanosheet units, unique hollow structures and abundant active Mo-N 4 species, that result in excellent activity with a half-wave potential of 0.86 V vs. RHE and superb stability for the oxygen reduction reaction in 0.1 M KOH; thus, the catalysts are promising air–cathode catalysts for Zn-air batteries with a high peak power density of 157.6 mW cm−2. [ABSTRACT FROM AUTHOR]

The illustration of Mo(VI) removal mechanisms by PPy-BT composite material to remove Mo (VI) mechanism. Electrostatic interactions and ion exchange contributed to the Mo(VI) removal. [Display omitted] The aim of current study was to develop a new material for the fast and efficient removal of hexavalent molybdenum (Mo(VI)) from contaminated water. In this work, a novel adsorbent was synthesized through the polypyrrole intercalation modification of bentonite (PPy-BT) via in-situ chemical polymerization method for effectively removal of Mo(VI) from aqueous solution. The surface morphology and chemical composition of PPy-BT composites were investigated by X-ray diffraction, energy-dispersive X-ray spectroscopy, Fourier transform infrared spectrometer, scanning electron microscopy techniques and X-ray photoelectron spectroscopy. PPy and BT could well resist the aggregation of each other, and therefore resulted in a loose-packed structure and good exposure of active sites. Using materials for the adsorption of Mo(VI) revealed has a maximum adsorption capacity of 100.17 mg/g at 25 °C and pH 4.0 by the Langmuir model. The adsorption kinetics and isotherm data are found to be well elucidated through pseudo-second-order and Langmuir models. Moreover, high regeneration ability (>89.3%) of PPy-BT was noted for five consecutive adsorption–desorption cycles. These findings highlight the potential of PPy-BT for practical water treatment applications. The intercalation material of PPy-BT could provide a new strategy to develop cost-effective clay-based nanomaterials for wastewater treatment. [ABSTRACT FROM AUTHOR]

[Display omitted] • The molybdenum oxynitride (MNO) thin films were prepared by a novel magnetron sputtering methods. • The deposited MNO thin films can be assembled in battery directly without non-conductive binders. • The MNO thin films show promising conductivity and superior electrochemical performance. • The Mo 2 N can effectively improve the electron transfer and ion diffusion in the MNO thin films electrode. With the fast development of flexible wearable electronics, mobile electronic equipment, electric tool and electric vehicles, high specific capacity, superior cycle stability and excellent fast-charge performance are required for lithium-ion batteries (LIBs). Nevertheless, commercial graphite with the limited theoretical capacity (372 mAh g−1) and short lifespan is difficult to satisfy the requirements of the new generation of LIBs. In this work, the three-dimensional flexible molybdenum oxynitride (MNO) thin films with non-binder were prepared by magnetron sputtering approach. The charge transfer resistance and Li-ion diffusion coefficient were measured by electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV), and the results show that molybdenum nitride is helpful to increase the diffusion and electron transfer of Li-ion. The MNO thin film annealed at 300 °C with irregular aggregate matrix structure shows a discharge capacity of 413 mAh g−1 after 180 cycles at 1 A g−1. The outstanding rate performance and cycle stability suggest that these binder-free thin film electrodes, especially nitrides, offer great opportunity for energy storage systems with fast-charge capabilities. [ABSTRACT FROM AUTHOR]

Neighborhood walkability may influence maternal-fetal exposure to environmental hazards and maternal-fetal health (e.g., fetal growth restriction, reproductive toxicity). However, few studies have explored the association between neighborhood walkability and hormones in pregnant women. We included 533 pregnant women from the Hangzhou Birth Cohort Study II (HBCS-II) with testosterone (TTE) and estradiol (E2) measured for analysis. Neighborhood walkability was evaluated by calculating a walkability index based on geo-coded addresses. Placental metals were measured using inductively coupled plasma mass spectrometry (ICP-MS). TTE and E2 levels in umbilical cord blood were measured using chemiluminescence microparticle immunoassay (CMIA). Linear regression model was used to estimate the relationship between the walkability index, placental metals, and sex steroid hormones. Effect modification was also assessed to estimate the effect of placental metals on the associations of neighborhood walkability with TTE and E2. Neighborhood walkability was significantly linked to increased E2 levels (P trend=0.023). Compared with participants at the first quintile (Q1) of walkability index, those at the third quintiles (Q3) had lower chromium (Cr) levels (β = −0.212, 95% CI = −0.421 to −0.003). Arsenic (As), cobalt (Co), manganese (Mn), molybdenum (Mo), nickel (Ni), lead (Pb), antimony (Sb), selenium (Se), tin (Sn), and vanadium (V) were linked to decreased TTE levels, and cadmium (Cd) was linked to increased TTE levels. No metal was significantly associated with E2 levels in trend analysis. In the analysis of effect modification, the associations of neighborhood walkability with TTE and E2 were significantly modified by Mn (P = 0.005) and Cu (P = 0.049) respectively. Neighborhood walkability could be a favorable factor for E2 production during pregnancy, which may be inhibited by maternal exposure to heavy metals. • Neighborhood walkability was linked to increased estradiol in umbilical cord blood. • Most placental metals were linked to decreased testosterone in umbilical cord blood. • Associations of neighborhood walkability with hormones were modified by metals. [ABSTRACT FROM AUTHOR]

Evidence increasingly suggests molybdenum exposure at environmental levels is still associated with adverse human health, emphasizing the necessity to establish a more protective reference dose (RfD). Herein, we conducted a study measuring 15 urinary metals and 30 clinical health indicators in 2267 participants residing near chemical enterprises across 11 Chinese provinces to investigate their relationships. The kidney and cystatin-C emerged as the most sensitive organ and critical effect indicator of molybdenum exposure, respectively. Odds of cystatin-C-defined chronic kidney disease (CKD) in the highest quantile of molybdenum exposure significantly increased by 133.5% (odds ratio [OR]: 2.34, 95% CI: 1.78, 3.11) and 75.8% (OR: 1.76, 95% CI: 1.24, 2.49) before and after adjusting for urinary 14 metals, respectively. Intriguingly, cystatin-C significantly mediated 15.9–89.5% of molybdenum's impacts on liver and lung function, suggesting nephrotoxicity from molybdenum exposure may trigger hepatotoxicity and pulmonary toxicity. We derived a new RfD for molybdenum exposure (0.87 μg/kg-day) based on cystatin-C-defined estimated glomerular filtration rate by employing Bayesian Benchmark Dose modeling analysis. This RfD is significantly lower than current exposure guidance values (5–30 μg/kg-day). Remarkably, >90% of participants exceeded the new RfD, underscoring the significant health impacts of environmental molybdenum exposure on populations in industrial regions of China. [Display omitted] • CYS-C was first identified as the critical effect indicator of Mo exposure. • CYS-C mediated 15.9–89.5% of molybdenum's impacts on liver and lung function. • Elevated Sr markedly attenuated the nephrotoxicity associated with Mo exposure. • The new RfD (0.87 μg/kg-day) was far lower than the current intake guidance values. • >90% participants faced non-carcinogenic risk from Mo exposure using the new RfD. [ABSTRACT FROM AUTHOR]

Accurate quantification of residual copper from inorganic copper reagents on the surface of citrus fruits is crucial for preventing diseases caused by excessive heavy metal intake. In this study, we developed a rapid colorimetric strategy for copper detection that is enhanced under near-neutral pH conditions, using molybdenum trioxide (MoO 3) and creatinine for copper-Fenton catalysis. The introduction of MoO 3 enriches the redox reactions of Cu2+/Cu+ within the complex formed by copper ions and creatinine, leading to enhanced copper-Fenton catalytic activity at near-neutral pH. In the presence of H 2 O 2 , this system oxidises colourless 3,3′,5,5′-tetramethylbenzidine (TMB) to blue oxTMB, thereby affording a sensitive colorimetric detection platform for Cu2+. The designed method offers high sensitivity for Cu2+ detection, with a linear range of 0.01 1.0 μg/mL and a detection limit as low as 0.007 μg/mL. This method was effectively used to analyse copper reagent residues on citrus surfaces, achieving recovery rates of 92.0% 115.0%. With its high sensitivity, selectivity, simplicity, and low cost, this colorimetric method shows great potential as an effective approach for determining copper ion levels, particularly for monitoring copper residues in agricultural products. [Display omitted] • Near-neutral pH copper Fenton-like catalytic chromogenic reaction of TMB-H 2 O 2. • Utilizes MoO 3 and creatinine for enhanced copper Fenton-like catalysis. • Enhanced sensitivity colorimetric detection of Cu2+ on citrus surfaces. [ABSTRACT FROM AUTHOR]

Single phytoremediation has limited capacity to restore soil contaminated with extreme Mo due to its low metal accumulation. Soil organisms can help compensate for this deficiency in Mo-contaminated soils. However, there is limited information available on the integrated roles of different types of soil organisms, particularly the collaboration between soil microorganisms and soil animals, in phytoremediation. The objective of this study is to investigate the effects of a combination of arbuscular mycorrhizal fungi (AMF) and earthworms on the remediation of Mo-contaminated soils by alfalfa (Medicago sativa L.). The results indicated that in the soil-alfalfa system, earthworms effectively drive soil Mo activation, while AMF significantly improve the contribution of the translocation factor to total Mo removal (TMR) in alfalfas (p < 0.05). Meanwhile, compared to individual treatments, the combination of AMF and earthworm enhanced the expression of alfalfa root specific Mo transporter - MOT1 family genes to increase alfalfa uptake Mo (p < 0.05). This alleviated the competition between P/S nutrients and Mo on non-specific Mo transporters-P/S transporters (p < 0.05). Additionally, the proportion of organelle-bound Mo in the root was reduced to decrease Mo toxicity, while the cell wall-bound Mo proportion in the shoot was increased to securely accumulate Mo. The contributions of inoculants to alfalfa TMR followed the order (maximum increases): AMF + E combination (274.68 %) > alone treatments (130 %). Overall, the "functional division and cooperation" between earthworm and AMF are of great importance to the creation of efficient multi-biological systems in phytoremediation. [Display omitted] • The competition of Mo and P/S limited alfalfa growth in 70-day cultivation period. • AMF enhanced alfalfa P/S uptake, stepwise boosted by earthworm through improving AMF colonization. • "Functional division" phenomenon was observed in phytoremediation. • Soil Mo transformation is dominated by earthworm, AMF was biased to transport Mo. • Co-inoculation activated MOT1 family genes expression to improve alfalfa Mo uptake. [ABSTRACT FROM AUTHOR]

Alkanotrophic Rhodococcus strains from the Regional Specialised Collection of Alkanotrophic Microorganisms (acronym IEGM, www.iegmcol.ru) were screened for accumulation and sorption of MoO 4 2- ions. Morphological and ultrastructural changes observed in bacterial cells during their cultivation in the molybdenum-containing medium are described. The species peculiarities, growth substrate preferences, and other physiological features allowing for the efficient removal of molybdate ions from the culture medium are discussed. Bioinformatics analysis of genes and proteins responsible for resistance to and accumulation of molybdenum was carried out using the sequenced R. ruber IEGM 231 and other published Rhodococcus genomes. n -Hexadecane growing strains with high (up to 85 %) accumulative activity and resistance to elevated (up to 20.0 mM) molybdenum concentrations were selected, which can be used for bioremediation of environments co-contaminated with heavy metals and hydrocarbons. Transmission electron microscopy and energy dispersive X-ray spectroscopy (TEM-EDX) revealed the ability of Rhodococcus not only to accumulate, but also to chemically convert soluble toxic molybdenum into insoluble compounds detected in the form of electron-dense nanoparticles. • Alkanotrophic Rhodococcus actively accumulate molybdenum ions. • Mo accumulation leads to changes in cellular ultrastructure and physiology. • High concentrations of Mo ions suppress the respiratory activity. • Rhodococcus can be used for Mo-containing wastewater treatment. [ABSTRACT FROM AUTHOR]

[Display omitted] • The co-dopants of Mo3+ (derived from Mo-C bonds) and pyridinic N together act as the active sites for OER process. • The relative contents of N dopants are regulated during carbon annealing under the NH 3 atmosphere. • Mo anchored N-doped carbon catalysts (denoted as Mo/NC-T) exhibit outstanding activity and durability in alkaline solution. Developing durable and efficient non-precious-metal based catalysts for oxygen evolution reaction (OER) is highly desirable in the field of electrocatalysis. In this work, a series of novel Mo anchored N-doped carbon catalysts (denoted as Mo/NC-T) were prepared starting from the zeolitic imidazolate framework 8 (ZIF-8) precursor. Firstly, Mo doped ZIF-8 precursor (Mo/ZIF-8) with a regular polyhedron structure was formed through a simple ion-exchange method process between molybdenum pentachloride (MoCl 5) and ZIF-8. Afterward, Mo/ZIF-8 was converted to Mo/NC-T through a two-step calcination process in nitrogen (N 2) and ammonia (NH 3). The as-synthesized Mo/NC-T samples exhibited superior electrocatalytic OER properties. The optimal sample at 650 °C (Mo/NC-650) presented a low overpotential of 320 mV at 10 mA cm−2, a Tafel slope of 71 mV dec-1, and an outstanding long-term stability for 30 h in 1 M KOH solution. The remarkable OER activity of Mo/NC-T could be ascribed to the structural stability of carbon matrix and the synergistic effect between Mo3+ (derived from Mo-C bonds) and pyridinic N. This work provides a novel perspective on the roles of Mo species in the N-doped carbon electrocatalysts for OER. [ABSTRACT FROM AUTHOR]

Laser-induced nitrogen-doped carbon-coated Mo/MoO 2 rods possess high-efficiency HER catalytic activity in a wide pH range. [Display omitted] Herein, a simple and fast laser-assisted coupling method is used for preparation of rod-like carbon-coated Mo/MoO 2 hybrids at room temperature and air environment. Under high energy of laser and reductive atmosphere caused by precursor decomposition, Mo-polydopamine complex-wrapped MoO 3 rods are quickly converted into nitrogen-doped carbon-coated Mo/MoO 2 rods. Carbon-coated Mo/MoO 2 exhibits high surface area, uniform metal dispersion and appealing hydrogen evolution reaction (HER) catalytic performance in a wide pH range. Carbon-coated Mo/MoO 2 shows overpotential of 134, 108 and 164 mV to deliver current density of 10 mA cm−2 under alkaline, acidic and neutral solution, respectively. Theoretical calculation demonstrates that combination of Mo and MoO 2 into Mo/MoO 2 composite favors the dissociation of water and adsorption of hydrogen. This study not only provides a high-efficiency strategy for preparation of electrocatalysts but also give guidance for development of hybrid electrocatalysts for HER. [ABSTRACT FROM AUTHOR]