Molybdate Nanoplates Research Articles

Bismuth Molybdate Nanoplates Supported on Reduced Graphene Oxide: An Effective Nanocomposite for the Removal of Naphthalene via Adsorption-Photodegradation.

Polycyclic aromatic hydrocarbons are a class of persistent organic water pollutants that raise serious concerns owing to their carcinogenicity and other negative impacts on humans and ecosystems. In this study, Bi2MoO6/reduced graphene oxide (rGO) nanocomposites were designed and prepared for the adsorption-assisted photodegradation of naphthalene molecules in an aqueous medium. The synthesized Bi2MoO6 nanoplates and Bi2MoO6/rGO nanocomposites were characterized by X-ray diffraction, Fourier transform infrared, scanning electron microscopy, high-resolution transmission microscopy, X-ray photoelectron spectroscopy, ultraviolet spectroscopy, Brunauer–Emmett–Teller, and photoluminescence measurements. The photodegradation of naphthalene molecules was observed to assess the photocatalytic characteristics of the samples under visible light. The Bi2MoO6/rGO nanocomposites exhibited significantly improved photocatalytic efficiency compared to pure Bi2MoO6. Among the nanocomposites, those containing 2 wt % rGO showed the best photocatalytic activity. The incorporation of rGO enhanced the visible light absorption and decreased the recombination rate of photogenerated charge carriers. Moreover, a Bi2MoO6/rGO nanocomposite showed excellent reusability for five cycles.

Copper molybdate synthesized by sonochemistry route at room temperature as an efficient solid catalyst for esterification of oleic acid

Copper molybdate nanoplates were synthesized by a sonochemical process at room temperature, which we report as a simple and cost-effective route. Structural analysis of the material by the Rietveld method of X-ray diffraction (XRD) data revealed lindgrenite Cu3(MoO4)2(OH)2 in a single-phase structure. All the vibrational modes characteristic of the space group were identified by Raman vibrational and near-infrared (NIR) spectroscopies. The profile obtained for N2 adsorption/desorption was type III hysteresis, characteristic of mesoporous materials, with a surface area of 70.77(1) m2 g−1. The micrographs of the material obtained by scanning electron microscopy showed nanoplates with nanometric sizes and an anisotropic growth aspect. The catalytic activity of lindgrenite was evaluated by esterifying oleic acid with methanol, showing high conversion rate to methyl oleate and good catalyst stability after seven recycling cycles. Above all, the best catalytic performance was reached when we optimized parameters such as oleic acid:methanol molar ratio of 1:5, 5% of catalyst dosage, and reaction time of 5 h, resulting in 98.38% of conversion at 413 K. Therefore, sonochemically synthesized lindgrenite proved to be a high potential material for biofuel production by oleic acid esterification.

Ultrasonication-aided synthesis of nanoplates-like iron molybdate: Fabricated over glassy carbon electrode as an modified electrode for the selective determination of first generation antihistamine drug promethazine hydrochloride.

The innovation of novel and proficient nanostructured materials for the precise level determination of pharmaceuticals in biological fluids is quite crucial to the researchers. With this in mind, we synthesized iron molybdate nanoplates (Fe2(MoO4)3; FeMo NPs) via simple ultrasonic-assisted technique (70kHz with a power of 100W). The FeMo NPs were used as the efficient electrocatalyst for electrochemical oxidation of first-generation antihistamine drug- Promethazine hydrochloride (PMH). The as-synthesized FeMo NPs were characterized and confirmed by various characterization techniques such as XRD, Raman, FT-IR, FE-SEM, EDX and Elemental mapping analysis and electron impedance spectroscopy (EIS). In addition, the electrochemical characteristic features of FeMo NPs were scrutinized by electrochemical techniques like cyclic voltammetry (CV) and differential pulse voltammetry technique (DPV). Interestingly, the developed FeMo NPs modified glassy carbon electrode (FeMo NPs/GCE) discloses higher peak current with lesser anodic potential on comparing to bare GCE including wider linear range (0.01-68.65µM), lower detection limit (0.01µM) and greater sensitivity (0.97 µAµM-1cm-2). Moreover, the as-synthesized FeMo NPs applied for selectivity, reproducibility, repeatability and storage ability to investigate the practical viability. In the presence of interfering species like cationic, anionic and biological samples, the oxidation peak current response doesn't cause any variation results disclose good selectivity towards the detection of PMH. Additionally, the practical feasibility of the FeMo NPs/GCE was tested by real samples like, commercial tablet (Phenergan 25mg Tablets) and lake water samples which give satisfactory recovery results. All the above consequences made clear that the proposed sensor FeMo NPs/GCE exhibits excellent electrochemical behavior for electrochemical determination towards oxidation of antihistamine drug PMH.

Rapid synthesis of bismuth molybdate nanoplates for supercapacitor applications by microwave combustion

Orthorhombic structured bismuth molybdate (Bi2MoO6) is obtained by one pot microwave combustion method. The characteristic performance of Bi2MoO6 nanocatalyst are described by X-ray diffraction (XRD), Scanning Electron Microscopy (SEM) furnished with Energy - dispersive X-ray spectroscopy (EDS) and Fourier change infrared (FT-IR) spectroscopy. The average crystallite size for Bi2MoO6 estimated from XRD is about 28.9 nm. The surface morphology from SEM pictures displays nanoplates. The FTIR is utilized to recognize the structural coordination and the presence of functional group. The electrochemical studies are taken to readily comprehend the electrochemical performance of the modified active electrode with notable specific capacitance value are found 234.9 Fg-1 at 5 mVs-1 and cyclic retention is stable up to 900 cycles (98.7 %). The as-synthesized dynamic material acts as a novel electrode material for supercapacitor.

Optimizing the synthesis of terbium(III) molybdate nanoplates through an orthogonal array design

The study focuses on the application of orthogonal array design for optimizing of the experimental parameters influencing the synthesis of terbium(III) molybdate nano‐plates through the direct precipitation method (DPM). The method conditions, included the concentrations of the cation and anion solutions (Cx and Cy), flow rate of adding the cation solution to that of the anion (Fx), and reactor temperature (Tz), were optimized in terms of the thickness of the produced nanoplates. Performing the analysis of variance (ANOVA) on the results revealed that the synthesis procedure can be optimized through using proper concentrations of the solutions (0.005 and 0.01 mol/L one‐to‐one for Tb(III) and ) as well as the reactor temperature (0 °C). The morphology and purity of the optimal product were also evaluated through X‐ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and fourier transform infrared spectroscopy (FT‐IR) spectroscopy. The results displayed that the thickness of the deposited terbium(III) molybdate nano‐plates is about 26 nm. The optimal product was also tested and found to be an efficient catalyst in the UV‐induced degradation of methyl orange (MO) by degrading about 97% MO after 80 min. © 2018 American Institute of Chemical Engineers Environ Prog, 38:e13091, 2019Highlights Terbium(III) molybdate nanoplates were fabricated via chemical precipitation route. Nanomaterial was synthesized without any surfactant, template, or catalyst. Synthesis process was optimized by Taguchi design to prepare nanoplates. Product nanoplate were characterized by TEM, XRD, FT‐IR, and DRS. Nanoplates were examined as photocatalyst to degrade organic pollution in water.

Statistical optimization of synthesis procedure and characterization of europium (III) molybdate nano-plates

Europium (III) molybdate nano-plates were synthesized in this work via chemical precipitation route involving adding of europium (III) ion solution to the aqueous solution of molybdate reagent. Effects of some reaction variables such as concentrations of europium and molybdate ions, flow rate of europium reagent, and reactor temperature on the diameter of the synthesized europium (III) molybdate nano-plates were experimentally investigated by orthogonal array design. The results showed that the size of europium (III) molybdate nano-plates can be optimized by adjusting the concentrations of europium (III) and molybdate ions, as well as the reactional temperature. Europium (III) molybdate nano-plates prepared under the optimum conditions were characterized by X-ray powder diffraction, scanning electron microscopy, and Fourier transform infrared spectroscopy.

Sodium chloride induced formation of square-shaped cadmium molybdate nanoplates

Square-shaped CdMoO4 nanoplates with an average size of ~4μm and thickness of ~200nm have been successfully synthesized via a NaCl-assisted hydrothermal method without using any surfactants or templates. X-ray diffraction pattern, scanning electron microscopy, transmission electron microscopy and UV–vis diffuse reflectance spectroscopy were used to characterize the samples. The formation process of CdMoO4 nanoplates is related to NaCl, which provides a favorable chemical environment for the growth of nanoplates.

ZnMoO4 Micro- and Nanostructures Synthesized by Electrochemistry-Assisted Laser Ablation in Liquids and Their Optical Properties

Electrochemistry-assisted laser ablation in liquids (ECLAL) is a chemically “simple and clean” synthesis of nanoparticles. Using ECLAL, we have synthesized zinc molybdate nanoplates and nanorods with two different phases. These two nanostructures are characterized carefully by scanning electron microscopy, transmission electron microscopy, X-ray diffraction analysis, Fourier transform infrared spectroscopy, Raman scattering spectroscopy, and UV–vis spectrophotometry. On the basis of the cathodoluminescence measurements, we observe that the nanoplates emit no light, while the nanorods give out green light before annealing. The optical properties of both get much better after annealing, which indicates their potential applications in photoelectric nanodevices. The basic physics and chemistry involved in the ECLAL fabrication and the luminescence mechanism for products before and after annealing are discussed.