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Comparing the Efficiency of N-Doped TiO2 and N-Doped Bi2MoO6 Photo Catalysts for MB and Lignin Photodegradation
摘要： In this study, we tested the efficiency of nitrogen-doped titanium dioxide (N-TiO2) and nitrogen-doped bismuth molybdate (N-Bi2MoO6) compounds as photocatalysts capable of degrading methylene blue and lignin molecules under irradiation with ultraviolet (UV) and visible light (VIS). Moreover, we compared TiO2 and Bi2MoO6 catalysts with N-TiO2 and N-Bi2MoO6 compounds using chemical coprecipitation. The catalysts were prepared starting from Ti(OCH2CH2CH3)4, Bi(NO3)3·5H2O, and (NH4)6Mo7O24 reagents. N-doping was achieved in a continuous reflux system, using ethylene diamine as a nitrogen source. The resulting materials were characterized using Scanning Electron Microscopy (SEM), X-Ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS). Additionally, we observed the decrease in particle size after processing the compounds in the reflux system. The results regarding photocatalytic degradation tests show a remarkable effect for nitrogen doped samples, achieving 90% of lignin degradation.
关键词： photocatalysis,lignin,visible light,UV light,bismuth molybdate,Titanium dioxide
更新于2025-09-23 15:23:52
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Exploration of structural, vibrational and spectroscopic properties of self-activated orthorhombic double molybdate RbEu(MoO4)2 with isolated MoO4 units
摘要： RbEu(MoO4)2 is synthesized by the two-step solid state reaction method. The crystal structure of RbEu(MoO4)2 is defined by Rietveld analysis in space group Pbcn with cell parameters a=5.13502(5), b=18.8581(2) and c=8.12849(7) ?, V=787.13(1) ?3, Z=4 (RB=0.86%). This molybdate possesses its phase transition at 817 K and melts at 1250K. The Raman spectra were measured with the excitation at l =1064 and 514.5nm. The photoluminescence spectrum is evaluated under the excitation at 514.5nm. The absolute domination of hypersensitive 5D0(cid:1)7F2 transition is observed. The ultranarrow 5D0(cid:1)7F0 transition in RbEu(MoO4)2 is positioned at 580.2nm being 0.2nm blue shifted, with respect to that in Eu2(MoO4)3.
关键词： Rietveld refinement,rubidium europium molybdate,Raman luminescence,solid state reaction,DSC
更新于2025-09-23 15:23:52
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Preparation and Enhancement of Luminescent Intensity of New Rare Earth Molybdate NaLa(MoO4)2:Eu3+ Phosphors
摘要： Novel red-emitting rare earth molybdate phosphors NaLa(MoO4)2:Eu3+ have been successfully synthesized by sol-gel method assisted by microwave. The as-synthesized samples were characterized by means of Fourier transform infrared spectroscopy, X-ray diffraction and Fluorescence spectrophotometer, respectively. The results show that the target product NaLa(MoO4)2:Eu3+ have been synthesized by calcining precursor at 800 oC. The obtained samples belong to tetragonal Scheelite-structure and I41/a space group. The excitation spectrum of NaLa(MoO4)2:Eu3+ has a broad band in the range of 250-350 nm and the main peak is at 301 nm. The broad band can be ascribed to the charge transfer band of Mo-O and Eu-O. The sharp lines in 350-500 nm range are due to 4f-4f transitions of Eu3+. The emission spectrum contains a series of narrow peaks, with the main peak at 616 nm originated from the electric dipole transition of 5D0 → 7F2 of Eu3+. The appropriate doping amount of Bi3+ and flux NH4F can enhance luminescent intensity of the sample effectively.
关键词： Rare earth molybdate,Sol-gel method assisted by microwave,Red-emitting phosphors,NaLa(MoO4)2:Eu3+
更新于2025-09-23 15:23:52
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Scandium Molybdate Microstructures with Tunable Phase and Morphology: Microwave Synthesis, Theoretical Calculations, and Photoluminescence Properties
摘要： In this paper, scandium molybdate microstructures have been prepared from solution via a microwave heating method. By controlling the experimental parameters such as molar ratio of reagent and reaction time, scandium molybdates with tunable phase and diverse morphologies including snowflakes, microflowers, microsheets, and branched spindles were obtained. The density of states and surface energies of Sc2Mo3O12 were primarily studied from first-principles calculations. An indirect band gap of 3.56 eV was observed for crystalline Sc2Mo3O12, and the surface energies of various facets were determined to be 0.27–0.91 J/m2. The influence of n(Sc3+):n(Mo7O24 6?) (short for Sc/Mo) molar ratio was systematically investigated and well-characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), and UV–vis absorption spectroscopy (UV–vis). Results indicate that the Sc/Mo molar ratio has a great effect on the phase and morphology. Diffuse reflection spectra (DRS) revealed the Egap can be readily tuned from 3.69 to 4.16 eV, which is in accordance with the theoretical result. The photoluminescence (PL) properties of Eu3+-doped Sc2Mo3O12 were discussed. This facile synthesis strategy could be extended to the synthesis of other molybdates.
关键词： photoluminescence,morphology control,microwave synthesis,scandium molybdate,density functional theory
更新于2025-09-23 15:23:52
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Ultrasound assisted deposition of highly stable self-assembled Bi2MoO6 nanoplates with selective crystal facet engineering as photoanode
摘要： The use of crystal facets of photocatalysts is well known as a promising strategy for the design of new photocatalysts with interesting physicochemical features for energy production applications. In this work, Bi2MoO6 thin films were synthesized by two methods, electrodeposition and sonoelectrodeposition. Preferential growth orientation depended on synthesis method. Results suggested that sonoelectrodeposition led to dominate the crystal facet {1 0 0} growth with self-assembled nanoplate morphologies while growth orientation in the {0 1 0} facet was dominant in electrodeposition in the absence of ultrasonic waves. As a highlight result, the {1 0 0} facet shows a smaller band gap, higher photocatalytic water splitting than the {0 1 0} facet. Efficient separation of charge pairs and long life time of photogenerated electrons was observed to be intrinsic features of the {1 0 0} facets. The higher charge transfer was confirmed by a higher photocurrent from linear sweep voltammetry and a smaller Nyquist radius arc. Ultrasound plays a key role in growth orientation and led to a production of homogeneous films with nanoplates which self-assembled together to form a flower-like structure. While in the absence of ultrasound the film has coral-like structure. Highly stable sonoelectrodeposited films exhibited incident photon-to-electron conversion efficiency (IPCE) of 22.4% at the specific wavelength of 500 nm. The sonoelectrodeposition method could act as a promising method for forming new films with specific crystal facet selection and developing as highly efficient photoanodes for PEC water splitting.
关键词： Crystal facet engineering,Coral-like,Water splitting,Bismuth molybdate,Self-assembled nanoplates,Sonoelectrodeposition
更新于2025-09-23 15:21:01
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High performance red/deep-red emitting phosphors for white LEDs
摘要： Highly efficient oxide based red line emitters are still bottleneck for the smart white LEDs. In the present investigation, sequences of narrow band red emitting phosphors were synthesized through the conventional solid-state technique. The X-ray diffraction studies reveals that the synthesized phosphors were crystallized in the trigonal phase with space group I41/a (88). Under 395 nm excitation, NaSrGd(MoO4)3:Eu3+ phosphors shown sharp red emission around at 616 nm because of the 5D0→7F2 transition (ED transition). Moreover, the internal quantum efficiency (IQE) was found to be 82 %, and the thermal stability study showed that the NaSrGd0.5Eu0.5(MoO4)3 phosphor retains the emission intensity around 71.5% at 423K of its initial room temperature. The red LEDs were designed for the NaSrGd0.5Eu0.5(MoO4)3 red phosphors with the NUV LED chip. White LED also been fabricated by conjugating the blue LED with yellow dye + red phosphor and the LED shown CCT (6823 K), CRI (74%), CIE (0.306, 0.331). The Sm3+ and Eu3+ co-doped deep red phosphor were synthesized and studied for the plant growth. The LED emission of Sm3+ and Eu3+ co-doped phosphor is completely covers the absorption spectrum of Phytochrome Pr. All of these consequences revealed that the synthesized phosphor could be the efficient red emitting phosphor for warm white LEDs and plant growth filed research.
关键词： Eu3+ red phosphor,Quantum Yield,White LED,Plant growth,Molybdate
更新于2025-09-23 15:19:57
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Hydrothermal Synthesis and Luminescent Properties of Spindle-Like NaGd(MoO <sub/>4</sub> ) <sub/>2</sub> :Eu <sup>3+</sup> Phosphors
摘要： Spindle-like NaGd(MoO4)2: Eu3 + phosphors with various Eu3 + concentrations were prepared via a hydrothermal process and characterized using X-ray diffraction (XRD) and field emission scanning electron microscopy (FE-SEM). The XRD results suggested that the prepared samples had a scheelite structure. The FE-SEM images indicated that the prepared NaGd(MoO4)2: Eu3 + phosphors were spindle-like. The influences of the ratio of sodium citrate and the rare earth cations on the product were studied. It was found that sodium citrate, as the chelating agent, could significantly influence the structure and morphology of the samples. The emission spectra, excitation spectra, fluorescence decay curves, and quantum yields of the samples were measured. The luminescent properties of the materials were studied. The results indicated that the electron–phonon coupling between the Eu3 + and the NaGd(MoO4)2 host was weak, and with the increase of the Eu3 + concentration, the Huang–Rhys factor increased. Additionally, the quantum efficiency of the Eu3 + 5D0 level was calculated, and it was found that the quantum efficiency decreased with the increase of the Eu3 + concentration.
关键词： Electron-phonon coupling,Rare earth,Hydrothermal,Molybdate,Luminescence
更新于2025-09-19 17:15:36
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[IEEE 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Chicago, IL, USA (2019.6.16-2019.6.21)] 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Unravelling Optical and Electrical Degradation of Perovskite Solar Cells and Impact on Perovskite/Silicon Monolithic Tandem Modules
摘要： The simultaneous measurement of heat and light signals from a scintillating crystal was performed at temperatures of tens of milli-kelvin using a scintillating bolometric detector. The crystal was instrumented with a pair of low-temperature detectors, consisting of a metallic magnetic calorimeter for reading the phonon signals and a light detector based on a Ge light absorber, to simultaneously measure the scintillation light and phonon signals. This article presents the principle and performance, such as the event separation capability, of this simultaneous heat/light measurement system.
关键词： low-temperature detector,Calcium molybdate,scintillation crystal,neutrinoless double beta decay,metallic magnetic calorimeters
更新于2025-09-19 17:13:59
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Fabrication of Luminescent Antireflective Coatings with CaMoO4:Eu3+/Ag Composite Structure
摘要： Highly transparent and luminescent CaMoO4:Eu3+/Ag composite films were fabricated on glass substrates as multifunctional antireflective (AR) coatings. The films were deposited through a combination of a sol–gel dip-coating technique and a hot water treatment. With the addition of an aluminum source in coating solutions, the sol–gel-derived films underwent a remarkable microstructural change during the hot water treatment due to the reaction between an amorphous alumina phase and water. This change brought both an antireflective effect (suppression of Fresnel reflection) and luminescence enhancement (suppression of total internal reflection) to the films. The introduction of Ag nanoparticles into the films further increased luminescence intensity without losing the antireflective effect.
关键词： calcium molybdate,silver nanoparticles,antireflective coatings,europium,nanocomposite,sol–gel method,photoluminescence
更新于2025-09-11 14:12:44
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[IEEE 2018 IEEE International Conference on Electro/Information Technology (EIT) - Rochester, MI, USA (2018.5.3-2018.5.5)] 2018 IEEE International Conference on Electro/Information Technology (EIT) - Electrochemical Phosphate Sensors Using Silver Nanowires Treated Screen Printed Electrodes
摘要： Essential biomolecules of the human body and plant growth depend upon the proper amount of phosphate ions. Phosphorus has critical values in both agricultural and biomedical applications. There is a need for inexpensive, portable, repeatable, highly sensitive and field deployable sensors with wide detection range to monitor the health of water system and to develop an electrochemical phosphate sensor using novel ammonium molybdate (AMT/AgNWs) modified screen printed electrode (SPE) for phosphate detection to achieve simplicity, high sensitivity, wide detection range, and high repeatability and portability. The cyclic voltammetry measurements exhibited the sensitivities of AMT modified SPE without and with AgNWs are 0.1 μA/μM and 0.71 μA/μM, respectively. The use of highly conductive AgNWs significantly increased the sensitivities of the AMT/SPE. Besides, AgNWs and AMT modified SPE (AMT/AgNWs/SPE) showed a very wide detection range of 5 μM -1 mM. Moreover, the proposed sensor demonstrated a good repeatability and recovery. Our work suggests that AMT/AgNWs/SPE is promising for simple, low-cost, and portable phosphate ion detection.
关键词： phosphate detection,ammonium molybdate,screen printed electrodes,electrochemical phosphate sensors,silver nanowires
更新于2025-09-10 09:29:36