Molybdenum Salt Research Articles

Ramie Degumming Waste‐Derived Biomass Carbon for High‐Performance Lithium–Sulfur Batteries

The application of lithium–sulfur batteries (LSBs) is still hampered by the shuttle effect of soluble lithium polysulfides (LiPSs) intermediates and slow redox kinetics. Therefore, in this work, a novel Mo,N co‐doped porous carbon (Mo,N‐C) was successfully synthesized by simply calcining a mixture of ramie degumming waste with cost‐effective molybdenum salt, and then employed as the LiPSs anchor. Due to the conductive carbon matrix, abundant porous structures as well as the doping Mo and N heteroatoms, the sluggish redox kinetic of the cathode has been significantly improved and the shuttle phenomenon of LiPSs has been effectively inhibited, consequently, the synthesized Mo,N‐C/S‐0.4 composite cathode could demonstrate a good initial capacity of 1379.2 mAh g‐1 at 0.2 C, and the reversible capacity could remain at 997.5 mAh g‐1 after 100 cycles. Even at a high discharge rate of 1.0 C, the capacity could remain at 700.2 mAh g‐1 after 400 cycles. This work provides a new avenue for utilizing the waste biomass on clean energy storage.

Polyoxometalate solution passivation enabling dendrite-free and high-performance zinc anodes in aqueous zinc-ion batteries

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 V2O5 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.

Cycad-leaf-like crystalline-amorphous heterostructures for efficient urea oxidation-assisted water splitting

Developing efficient bifunctional catalysts for urea oxidation reaction (UOR)/hydrogen evolution reaction (HER) is important for energy-saving hydrogen production. Herein, a catalyst with crystalline-amorphous heterostructure supported by NiCo alloy on nickel foam (NiCoO-MoOx/NC) is reported for the first time. Through simple molybdenum salt etching, 2D NiCo alloy nanosheets are transformed into a unique 3D cycad-leaf-like structure with a super-hydrophilic surface. Simultaneously, the synergistic effect between crystalline NiCoO and amorphous MoOx improves the UOR and HER activity, merely requiring 1.28 V and −45 mV potentials to reach ±10 mA cm−2, respectively. Particularly, the UOR kinetics of NiCoO-MoOx/NC is enhanced significantly compared to that of NiCoO/NC. The electronic structure of NiCoO is modified by MoOx, enabling the rapid generation of NiOOH and CoOOH active species, which would accelerate the synergistic electrocatalytic oxidation of urea molecules. This work inspires the design of highly active and stable bifunctional catalysts for urea assisted H2 production.

Dual template-derived 3D porous Co6Mo6C2/Mo2C@NC framework for electromagnetic wave response and multifunctional applications

The swift advancement of electronics technology has led to a burgeoning interest in multifunctionalizing electromagnetic wave (EMW) absorption materials as a prospective avenue for future development. However, the effective integration of diverse functions within a single material continues to present challenges. This work successfully fabricated a three-dimensional (3D) porous Co6Mo6C2/Mo2C@NC framework with carbon microspheres through uncomplicated freeze-drying and high-temperature pyrolysis techniques. The resultant magnetic bimetallic carbide (Co6Mo6C2 and Mo2C) nanoparticles are uniformly and densely embedded within the carbon layer, facilitated jointly by a rigid template (molybdenum salt) and a flexible template (glucose), thus realizing an exceptional dual loss mechanism involving dielectric and magnetic components. The establishment of the 3D porous conductive network enhances EMW absorption through multiple reflections and scattering mechanisms. Impressively, the Co6Mo6C2/Mo2C@NC framework attains remarkable EMW absorption characteristics with ultralightweight (0.1567 g cm–3), ultrathin matching thickness (1.7 mm), and robust absorption (reflection loss RL value of –65.89 dB). Furthermore, it achieves a noteworthy effective absorption bandwidth (EAB, RL ≤ –10 dB) spanning 6.4 GHz, ensuring complete absorption of 100 % within the X band (8–12 GHz) at a matching thickness of 2 mm. In addition, the Co6Mo6C2/Mo2C@NC framework exhibits pronounced hydrophobicity and magnetic responsiveness, bestowing upon it appealing attributes including self-cleaning, flame retardancy, and thermal insulation, on par with those observed in commercial products. The radar cross-sectional area (RSC) reduction value of the Co6Mo6C2/Mo2C@NC framework can reach 35.2 dB m2 by RSC simulation, which can effectively lower the likelihood of detection by radar detectors for the target. This study presents a viable strategy for the advancement of novel lightweight and multifunctional materials that demonstrate exceptional performance in absorbing electromagnetic waves.

Highly selective and efficient hydrogenation of fatty acids to alcohols using NiMo@C catalyst

Selective hydrodeoxygenation is the central challenge in converting bio-derived fatty acids into fatty alcohols under mild conditions. Herein, an effective and highly selective carbon-supported NiMo catalyst (NiMo@C) was developed by the thermolysis Ni-based metal–organic frameworks (MOF) impregnated Mo species. At a low temperature of 160 °C, the stearic acid can be efficiently converted into corresponding stearic alcohols over the NiMo@C with about 97% selectivity at 100% reactant conversion, which is superior to the most reported catalysts containing noble catalysts. The excellent catalytic performance of NiMo@C catalyst was mainly attributed to the ordered arrangement of Ni in the MOF and the uniform loading of molybdenum salt, which leads to an ideal distribution of Ni and Mo after pyrolysis of the MOF. The carbon support also prevents the aggregation of metal particles, which promotes the dissociation of hydrogen and enhances the synergy between Ni and Mo sites. More importantly, the synthesized NiMo@C catalyst showed excellent reusability with no loss of activity after 15 consecutive runs due to the stability of the catalyst structure. This provides a useful and simple method for synthesizing highly efficiency and stable NiMo@C bimetallic catalysts, which can facilely and selectively hydrogenate the bio-derived fatty acids to corresponding alcohols under mild conditions.

Facile synthesis of ammonium-decorated cobalt molybdenum fluoride as electroactive material of supercapacitor

Bimetallic fluorides are widely applied as the electroactive material of the supercapacitor (SC) due to abundant redox states and high electrical conductivity as clean renewable energy. Ammonia fluoride is regarded as the structure-directing agent for modulating morphology as well as providing F− and NH4+ to respectively form fluoride and hydrogen bonding with promoted electricity transfer routes. In this study, ammonium-decorated cobalt molybdenum fluoride (CoMoFN) is firstly synthesized using the molybdenum salt and the zeolitic imidazolate framework 67 (ZIF67) derived perovskite prepared using NH4F in the hydrothermal process as the active material of the SC. Molybdenum can enhance electrical conductivity and cyclic stability, as well as confines NH4+ in the framework. Hydrogen bond between NH4+ and F− could promote charge transfer, but the steric hindrance of NH4+ could prohibit ion diffusion. The optimal CoMoFN presents the preferable one-dimensional nanowires-embedded film-like structure, and achieves a specific capacity (CF) of 33.7 mAh/g at 20 mV/s, while the electrode synthesized without Mo shows a smaller CF value of 17.8 mAh/g. A symmetric SC composed of CoMoFN electrodes shows a maximum energy density of 6.44 Wh/kg at 0.7 kW/kg. Excellent cycling stability with the CF retention of 73% and the Coulombic efficiency higher than 99% after 6500 times charge/discharge processes are also achieved. This work provides significant information about functions of NH4+ on energy storage. It is expected to synthesize more efficient materials based on NH4+ for the energy storage devices.

NaCl-Assisted Ultrasmall Mo2C Nanocrystals Confined in N, S Double-Doped Hierarchical Porous Carbon for Efficient Hydrogen Generation

Refining the size of nonprecious metal-based catalysts and restricting them in multiheteroatom-doped hierarchical porous carbon can achieve efficient electrical energy conversion. In this study, ultrasmall Mo2C nanocrystals with an average size of 4.9 nm are fitted to N and S double-doped hierarchical porous carbon (us-Mo2C/N,S-HPC) through a template strategy and used for efficient hydrogen production. First, the metal molybdenum salt is captured and fixed by natural bamboo leaf fibers which are pulverized by a ball mill. Meanwhile, the soluble sodium salt is largely filled in the bamboo leaf tissue. Subsequently, Mo2C nanocrystals formed by high-temperature reduction are uniformly anchored on the bamboo-derived N, S double-doped hierarchical porous carbon. As a result, the prepared us-Mo2C/N,S-HPC requires 150, 197, and 148 mV overpotential to drive a current density of 10 mA cm–1 at pH = 0, 7, and 14, respectively. This improvement is attributed to the synergistic effects of size controllable Mo2C, multidoped heteroatoms, and multiscale assembly structures. Significantly, this study is conducive to the construction of ultrafine nanocrystals and the high-value conversion of waste biomass.

Study of formation of valuable organic products from bioremediation of chlorpyrifos by bacteria catalyzed by molybdenum and zinc salt

Experimental studies have been carried out to find the bioremediation activity of bacteria with molybdenum and zinc ions separately on the toxic insecticide, chlorpyrifos. Two bacterial strains, ZS20 (Enterobacter sp. strain TSNG) and E57 (Pseudomonas sp. strain GRTM) and three inorganic salts: ammonium-molybdate, sodium-molybdate, and zinc-nitrate, have been used for the degradation of toxic insecticide, chlorpyrifos. The metabolic products obtained are chelating organic acids, such as maleamic acid, ascorbic acid, salicylic acid, and other different derivatives of soluble-phosphate and phosphatase enzymes. They help for the better growth of plants. Ammonium-molybdate along with ZS20 strain is more active for the production of metabolic products and the growth of plants than the other combination. The liquid chromatography and mass spectrometry data of ZS20 and ammonium-molybdate salt portray complete degradation of chlorpyrifos into nontoxic valuable products. Hence, this combination can be used as good bioremediater as well as good biofertilizer. Results have been tabulated, shown graphically and discussed.

Multi-channel-contained few-layered MoSe2 nanosheet/N-doped carbon hybrid nanofibers prepared using diethylenetriamine as anodes for high-performance sodium-ion batteries

A facile new strategy for the synthesis of multi-channel-contained N-doped carbon nanofibers composed of few-layered MoSe2 nanosheets (denoted as MC-NCNF/MoSe2) was introduced and the composite was demonstrated as an anode material for sodium-ion batteries. This was the first time that diethylenetriamine was introduced as a pore generator in the electrospinning process and played a key role in generating multi-channels in the structure by phase-separation from the molybdenum salt and subsequent volatilization without any additional process. Polyvinylpyrrolidone was used as a carbon precursor and played the role of a N-doping source for the carbon matrix. MC-NCNF/MoSe2 achieved a high reversible discharge capacity of 386 mA h g−1 at a current density of 0.5 A g−1 after the 300th cycle and superior rate capability of 285 mA h g-1 at 10.0 A g−1. The multi-channeled structure of MC-NCNF/MoSe2 facilitated effective Na+ and electron diffusion during repeated discharge/charge processes and accommodated the huge volume expansion of the MoSe2 nanosheets induced by electrochemical reaction of the Na+ ion.

Mo2C and Its Composites Derived from Egg White for Hydrogen Evolution Reaction at All pH Range

AbstractSearching for biomass‐derived electrocatalyst with high activity and durability for hydrogen evolution reaction (HER) at all pH range is extremely desirable but remains a significant challenge. Mo2C and its nanocomposites have been controlly synthesized by pyrolyzing the mixture of molybdenum salt and egg white (EW) that served as low‐cost but environmental‐friendly carbon source. When utilized as hydrogen evolution cathode, Mo2C and its nanocomposites exhibit excellent electrocatalytic activity and stability in acidic, neutral and alkaline mediums.

PHENOL TOLERANCE AND BIODEGRADATION OPTIMIZATION OF Serratia marcescens NSO9-1 USING PLACKETT-BURMAN AND BOX-BEHNKEN DESIGN

The phenol degradation capacity of Serratia marcescens NSO9-1 isolated from olive mill wastewater was evaluated and optimized in this study. Plackett-Burman design coupled with Box-Behnken methodology was used to evaluate the effects of medium components and significant parameters on phenol degradation by this relevant strain. According to Plackett-Burmanbased statistical screening, seven of the eleven components of the medium had a significant effect on the metabolism of phenol degradation. The most important factors were MgSO4, NaCl, CaCl2, and molybdenum salt, which had an effective contribution of 90.12%. Additionally, Box-Behnken methodology using a quadratic model was adopted to investigate the mutual interactions between process parameters. The analysis results indicated that interactions between pH and temperature, pH and inoculum amount, and incubation time and inoculum amount critically affected the response variable. The experimental results showed that under the determined conditions, 41.66% of the maximum removal efficiency of phenol was achieved. The optimal conditions were 8.94, 30.22 C, 4.19 days, and 4.68% (v/v) for pH, temperature, incubation time, and inoculum amount, respectively. The validity and practicability of this statistical optimization strategy confirmed the relation between predicted and experimental values. Using a selective isolation method, the performance of this indigenous strain isolated from olive oil mill wastewater, which contained polyphenolic compounds, is comparable to the reported literature at higher phenol concentrations.

Reduction of sulfur content in shale oil by oxidative desulfurization

The oxidative desulfurization of shale oil obtained by thermal extraction of organic matter from shale rock using an oxidative catalytic system composed of hydrogen peroxide, a molybdenum salt, and acids of different natures has been studied. It has been shown that the application of this method in combination with extraction of the oxidation products of organic sulfur compounds makes it possible to remove up to 94% of total sulfur from the synthetic oil.

Synthesis, crystal structure and characterization a new ionic complex MoO2Cl3(MeOH)·H3tptz·Cl2 (tptz = 2,4,6-tris(2-pyridyl)-1,3,5-triazine) as epoxidation catalyst

[MoO2Cl3(MeOH)]·H3tptz·Cl2 (1) (where tptz is 2,4,6-tris(2-pyridyl)-1,3,5-triazine) was prepared via reaction of MoO3 with tptz in a stoichiometric ratio of 1:1 in concentrated HCl at room temperature. It was characterized, by means of elemental analysis, FTIR, UV–Vis, 1H NMR and single-crystal X-ray diffraction. The asymmetric unit of the molybdenum(VI) salt 1 contains a 2,2′,2″-(1,3,5-triazine-2,4,6-triyl)tripyridinium cation, a cis-dioxotrichloridomethanolmolybdenum(VI) monoanion and two chloride anions to achieve electrical neutrality. The oppositely charged components in the structure of 1 are bound together by an intricate system of weak N(O)–H⋯Cl hydrogen bonds. The interactions between hydrogen bond donor and acceptor giving rise to three dimensional networks. It was also found that compound 1 successfully catalyzes the epoxidation of various alkenes such as cycoloctene, cyclohexene, norbornene, styrene, α-methyl styrene and trans-stilbene with 30–100% conversion and 80–100% selectivity using tert-butyl hydroperoxide (TBHP) as oxidant. The catalyst can be easily recovered from the reaction mixture and reused at least for three times without significant loss of activity. The superior antibacterial activity of 1 against Bacillus subtilis is also described in this presentation.

SCR of NO by NH3 catalyzed by Mo- and V-exchanged zeolite: Effect of Mo precursor salt

V and Mo exchanged H+–ZSM-5 (Si/Al = 15) zeolite catalysts, prepared by solid-state ion exchange of ammonium metavanadate (2 wt.%) and different molybdenum salt precursors (acetylacetonate, oxide, carbonyl and chloride, molar ratio V/V + Mo = 2/3), were tested in the SCR of NO by NH3. Using [CH3COCHC(O–)CH3]2MoO2 like-precursor, acetylacetonate ligands extracted Al atoms from the zeolite framework and the formation of Al2(MoO4)3 was therefore extended. In the SCR of NO, such an undesired phase as well as crystalline MoO3 inhibited the diffusion of reactants. Starting from MoO3 and Mo(CO)6 precursors, the formation of small amounts of Al2(MoO4)3 is considered. However, the sublimation of Mo(CO)6 during the solid-state exchange avoided the agglomeration of Al2(MoO4)3 and the catalytic performance was therefore improved. The catalyst issued from MoCl3 is highly active in the studied reaction. V2O5 and Mo–V–O species are plausible active sites, while Al2(MoO4)3 and MoO3 oxide could be avoided during the exchange of MoCl3 into H+–ZSM-5.

Molybdenum complexes derived from the oxydianiline [(2-NH2C6H4)2O]: synthesis, characterization and ε-caprolactone ROP capability.

The reaction of Na2MoO4 with 2,2'-oxydianiline (2-aminophenylether), (2-NH2C6H4)2O, LH4, in DME (DME = 1,2-dimethoxyethane) in the presence of Et3N and Me3SiCl afforded either the bis(imido) molybdenum(vi) complex {Mo(L)Cl2(DME)} (), where L = (2-NC6H4)2O, or the molybdenum(v) salt [Mo(L')Cl4][Et3NH] (), where L' = [(2-NH2C6H4)(2-NC6H4)O], depending on the work-up method employed. The same diamine reacted with in situ [Mo(NtBu)2Cl2(DME)] afforded a tetra-nuclear complex [Mo4Cl3(NtBu)3(OSiMe3)(μ4-O)(L)2(L')2]·2MeCN (·2MeCN). The crystal structures of , and ·2MeCN have been determined. The structure of the bis(imido) complex contains two unique molecules paired up via weak π-stacking, whereas the structure of contains a chelating amine/imido ligand, and is made up of discrete units of two cations and two anions which are interacting via H-bonding. The tetra-nuclear structure contains four different types of distorted octahedral molybdenum centre, and a bent Me3SiO group thought to originate from the precursor synthesis. Complexes have been screened for their ability to ring open polymerize (ROP) ε-caprolactone. For and (not ), conversion rates were good (>90%) at high temperatures (100 °C) over 6-24 h, and the polymerization proceeded in a living manner.

Inhibitory impact of plant nutritional compounds on Xanthomonas citri subsp. citri, the causal agent of bacterial canker of citrus

Six essential plant micronutrients, copper (Cu), iron (Fe), zinc (ZN), manganese (MN), molybdenum (Mo) and boron (B) salt compounds, were investigated for their potential antibacterial activity against a group of 32 Xanthomonas citri subsp. citri (Xcc) isolates, as representative of the Iranian population of bacterial of citrus canker disease agents, and the sensitivity patterns of the isolates were characterized. For all tested compounds, a significant antibacterial activity against representative Xcc strains was determined. Bacterial growth was severely inhibited by Cu, Fe, Zn, Mn and Mo at 1/2 MIC, MIC and MBC concentrations, whereas B had only a moderate to slight impact. Among the salt compounds, Zn had the lowest MIC (0.6-1.25 mM) and MBC (2.5 mM). The highest MIC and MBC values were obtained for Mo at the dose of 30-40 mM and 40-50 mM, respectively. The results showed that 62.5% of the tested bacterial isolates were less susceptible to Fe, Zn, Mn and Mo and more susceptible to Cu and B. Nevertheless, only 37.5% of them showed a high degree of susceptibility to most of the compounds.

Molybdenum/graphene – Based catalyst for hydrogen evolution reaction synthesized by a rapid photothermal method

Catalysis of the hydrogen evolution reaction (HER) is important in the development of an energy economy based on clean hydrogen gas. In this work, we report a new catalyst material for the generation of hydrogen via hydronium reduction. The new material, which consists of MoO 2 , sulfur, and graphene, was prepared by co-reduction of molybdenum salt and graphite oxide in air in the presence of focused solar radiation. The potential utility of this material for HER catalysis was evaluated by cyclic and linear-sweep voltammograms and compared against a Pt/C commercial catalyst. The MoO 2 /graphene hybrid nanocomposite exhibits a Tafel slope of 47 mV/dec and hydrogen evolution at a potential only ∼120 mV more negative than the standard Pt/Carbon catalyst at 10 mA/cm 2 current density. The hydrogen gas generated by the catalytic material was measured using gas chromatography. The simple synthesis and low overpotential suggests that this hybrid composite has potential as an HER catalyst. • A mixture of MoO 2 , sulfur and graphene has been prepared with natural sunlight. • XRD, SEM, EDX and FTIR validate material composition. • The high material surface area is advantageous for HER processes. • The material has favorable overpotential and Tafel slope values for catalysis. • The stability, activity, and green synthesis are favorable for clean energy.

Research on the fertilizer demand and on the influence of detergent on sweet pea (Lathyrus odoratus L.) cv. 'Wirlarind', grown in hydroponic cultures

The plants were grown in vessels composed of two parts: in the upper one, with the perforated bottom, was mixture of peat with brown coal or peat with scoria, and in the lower one - a nutrient solution to a height of 12 cm. The lowering of nitrogen fertillization (to 43%) and the increase in the molybdenum salt dose produced a positive difference in yield. A 3,7 g dose of fertilizer mixture per plant during the vegetation season has been found to be optimum. The detergent, when applied only once, improved the crop quality. When applied every fourth week, it caused a decrease in the number of racemes per plant grown on a slag~peat seedbed, whereas, on the lignitepeat seedbed all the detergent action was annulled.

Hydrogen generation by hydrolysis of alkaline NaBH4 solution on Co–Mo–Pd–B amorphous catalyst with efficient catalytic properties

Mo-modified Co–Pd–B (Co–Mo–Pd–B) and Pd-modified Co–B (Co–Pd–B) catalyst powders are synthesized by chemical reduction of cobalt and molybdenum salt at ambient conditions. The resulting catalyst powders are characterized by scanning electron microscopy (SEM), X-ray powder diffraction (XRD), X-photoelectron spectroscopy (XPS) and BET surface area measurement. The study on the catalytic efficiency of amorphous Co–Mo–Pd–B catalyst powders is performed in hydrogen generation by hydrolysis of alkaline sodium borohydride (NaBH4). The Co–Mo–Pd–B powders show the highest hydrogen generation rate as compared to Co–B, Co–Mo–B, and Co–Pd–B catalyst powders. Kinetic studies on the hydrolysis reaction of NaBH4 with Co–Mo–Pd–B catalyst reveal that the concentrations of both NaBH4 and NaOH have essentially no evident effects on hydrogen generation rate. The promoting effect of Mo in Co–Mo–Pd–B catalyst results in lower activation energy for hydrogen production, which is 36.36kJmol−1 compared to 64.87kJmol−1 obtained with pure Co–B powder.

Rapid, one pot preparation of d-mannose and d-mannitol from starch: the effect of microwave irradiation and Mo VI catalyst

The effect of microwave irradiation upon starch hydrolysis and simultaneous epimerization of the d-glucose to d-mannose obtained was investigated. An acidic aqueous solution of starch was treated with a catalytic amount of hexavalent molybdenum salt in microwave field and the composition of the reaction mixture was analyzed. Rapid starch hydrolysis and subsequent epimerization provided an equilibrium reaction mixture of d-glucose and d-mannose (2:1) without the formation of any undesirable by-products. The reduction of d-mannose with sodium borohydride yielded d-mannitol in very good yield. Microwave irradiation proved to be an efficient tool for the transformation of starch to mannose over an Mo VI catalyst. This method has the advantages of environmental friendliness, easy operation, good yields and substantial reduction of reaction time.