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Microstructure property study of ZnO single crystal irradiated with 200 MeV 86Kr17+ ions
摘要： ZnO single crystal materials irradiated with 200 MeV energy 86Kr17+ ions have been analyzed by a series of theoretical calculations, Raman spectroscopy and TEM tests, etc. After irradiation by 200 MeV 86Kr17+ ions, two broad vibrational absorption peaks appeared and there is no obvious change in other characteristic peaks. By measuring the Raman spectra of the incident light perpendicular to and parallel to the z axis of the crystal, it was proved that the vibration absorption peak of 526 cm-1 ~ 600 cm-1 is caused by defects related to oxygen vacancy (VO). The experimental data fully proved that ZnO single crystal has good radiation resistance. These data are of great significance for the application of ZnO materials in various new devices in the future.
关键词： ZnO,Transmission electron microscopy,Raman spectra,86Kr17+ ions irradiation
更新于2025-09-23 15:21:01
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High Charge Carrier Storage Capacity in Lithium Lutetium Silicate Doped with Cerium and Thulium
摘要： It is demonstrated that LiLuSiO4:Ce,Tm has excellent charge carrier storage properties. Comparative studies are performed with the state-of-the art X-ray storage phosphor BaFBr(I):Eu. The thermoluminescence (TL) intensity of the optimized LiLuSiO4:Ce,Tm is four times higher than the TL of BaFBr(I):Eu. After 3 h of storage at room temperature (RT) there is still 94% of initial thermoluminescence and only 48% for BaFBr(I):Eu which demonstrates insignificant thermal fading. The signal can be read out by a blue LED and less efficiently by a red laser. It does require higher stimulation energy than in the case of BaFBr(I):Eu. The self-irradiation with a dose rate of 13 mGy h due to 176Lu isotopes is not a serious drawback for application.
关键词： storage phosphors,thulium,cerium,traps,thermoluminescence,fading,self-irradiation
更新于2025-09-23 15:21:01
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Atomic diffusion induced by electron-beam irradiation: An <i>in situ</i> study of Ag structures grown from <i>α</i> -Ag <sub/>2</sub> WO <sub/>4</sub>
摘要： In this paper, we investigate the structural and morphological changes caused by the electron-beam irradiation that led to the growth of complex extruded filaments on the surfaces of α-Ag2WO4. To provide a complete description of this phenomenon, both scanning electron microscope (SEM) and transmission electron microscope (TEM) were employed in this study. Our experimental results evidenced that the extruded material was able to growth in different crystallographic faces, depending on the kind of microscope adopted during the electron-beam irradiation. For a more complete analysis, different electron-beam current densities in TEM were used to investigate all in situ modifications in the microcrystals. For the first time, besides the metallic silver, the presence of silver oxides (Ag2O and Ag3O4) were detected in the composition of extruded material. The diffusion mechanisms related to morphological modifications in the samples irradiated in SEM and TEM were discussed in details. The co-precipitation reaction in dimethyl sulfoxide was chosen as synthetic route, which favored the appearance of rectangular rod-like α-Ag2WO4 microcrystals. A growth mechanism was proposed to explain the formation and growth processes of these microcrystals.
关键词： silver filaments,α-Ag2WO4,silver oxides,electron-beam irradiation,diffusion mechanisms
更新于2025-09-23 15:21:01
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{0 0 1}-Facet-Exposed Ag <sub/>4</sub> V <sub/>2</sub> O <sub/>7</sub> Nanoplates: Additive-Free Hydrothermal Synthesis and Enhanced Photocatalytic Activity
摘要： The synthesis of silver pyrovanadate, Ag4V2O7, nanoplates with exposed {0 0 1}-facets by a facile, additive-free hydrothermal method was described in this paper. The photocatalytic activity of rhodamine B over Ag4V2O7 samples under solar light irradiation was also evaluated. By using an equimolar mixture of NH4VO3 and AgNO3 with the presence of a suitable amount of ammonia, Ag4V2O7 nanoplates were obtained readily and purely at temperatures from 100 to 140°C for 4 h. The c-axis orientation growth of Ag4V2O7 nanoplates occurred and increased monotonously with temperatures in the range of over 100 up to 140°C. Further increase in hydrothermal temperature up to 220°C, the Ag4V2O7 phase no longer existed and the β-AgVO3 phase was formed instead. The photocatalytic activity of the optimized Ag4V2O7 sample comprising {0 0 1}-facet-exposed nanoplates with the highest degree of orientation was significantly higher than that of the random-oriented sample. The effects of using ammonia as a complexing agent on the structure, microstructure, texture, exposed facet, and photocatalytic activity of Ag4V2O7 samples were also investigated for the first time.
关键词： photocatalytic activity,hydrothermal synthesis,Ag4V2O7,rhodamine B,nanoplates,solar light irradiation
更新于2025-09-23 15:21:01
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Visible-Light-Mediated Photoredox-Catalyzed Regio- and Stereoselective Chlorosulfonylation of Alkynes
摘要： Herein, a one-step chlorosulfonylation of alkynes via a photocatalytic redox process is described. A variety of commercially available sulfonyl chlorides can be applied for the generation of sulfonyl radical species under visible-light irradiation. Regio- and stereoselective addition of the sulfonyl radical and chloride leads to the e?cient formation of (E)-selective β-chlorovinyl sulfones from a broad range of terminal and internal alkynes. The reported method represents an operationally simple and mild way to furnish vinyl sulfones.
关键词： photoredox catalysis,vinyl sulfones,chlorosulfonylation,alkynes,visible-light irradiation
更新于2025-09-23 15:21:01
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Synthesis, Characterization of SiO2/TiO2 and SiO2/Al2O3 Nano-Composites for the Photo-Degradation of Acid Brown- 43 dye with Irradiation of Solar Light
摘要： In this study we have found that photo degradation of Acid brown- 43 dye with irradiation Solar light Using synthesized SiO2/ TiO2 and SiO2/Al2O3 Nano-composites which prepared by chemical precipitation technique using microwave irradiation. The structure and morphology of SiO2/TiO2 and SiO2/Al2O3) Nano composites were characterized by SEM, EDAX & TEM analysis. The similarities in photo degradation mechanism, SiO2, Al2O3 and TiO2 have as good as band gap energy, and possess worthy standing as photo-catalysts. SiO2/TiO2 and SiO2/Al2O3 nanoparticles have large surface area and thus provide a large number of active sites for interaction among the particles of different oxides. This synthesized Nano-composites of SiO2/TiO2 and SiO2/Al2O3 photo-catalyst sample showed tremendous photo-catalytic activity for the degradation of Acid Blue-43 under direct exposure to solar irradiation with respect to exposed time and dose of Nano-composites.
关键词： Acid brown–43,Photo-degradation,solar irradiation,Nano-composite
更新于2025-09-23 15:21:01
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PRECISE FINITE DIFFERENCE ANALYSIS OF LORENTZ FORCE ACTING ON METAL NANOPARTICLE IRRADIATED WITH LIGHT
摘要： A ?nite di?erence method in the frequency domain is evaluated to clarify characteristics of the Lorentz force exerted on a metal nanoscale particle by light irradiation. Numerical results are compared with exact values obtained from Mie theory to show that applying a smoothing algorithm to the surface of a nanoparticle increases the accuracy of the simulation. Analysis of the Lorentz force exerted between two spheres aligned closely indicates that strong forces cause the spheres to attract each other at the plasmon resonant frequency. It was also noticed that application of the smoothing algorithm was indispensable in order to achieve the above result.
关键词： plasmon resonance,finite difference method,Lorentz force,light irradiation,metal nanoparticle,Mie theory
更新于2025-09-23 15:21:01
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Improvement of photocurrent and progesterone degradation by employing WO3 films modified with platinum and silver nanoparticles
摘要： The effect of silver (Ag0) and platinum (Pt0) metallic nanoparticles (NPs) on WO3 film was investigated by studying the photocurrent response under polychromatic irradiation. The structural phase revealed by X-ray diffraction (XRD) analysis indicates a monoclinic crystal nanostructure. WO3, Ag0/WO3, and Pt0/WO3 electrodes were used to degrade 0.35 mg L-1 progesterone hormone in aqueous solution under polychromatic irradiation for 3h. These studies on degradation were investigated under conditions of heterogeneous photocatalysis (HP) and electrochemically assisted HP (EHP). For photodegradation of progesterone, higher performance was achieved when WO3 was functionalized and when the EHP configuration was adopted with bias at +0.7 V vs Ag/AgCl. This work reveals that the incorporation of metallic NPs onto a semiconductor increases its efficiency, preventing electron-hole recombination in the photocatalyst and photoelectrochemical limitations of WO3 due surface plasmon resonance (SPR) and the trapping state. Therefore, efficient advances in the degradation of organic contaminants during water treatment can be realized based on this study.
关键词： Progesterone photodegradation,Polychromatic irradiation,Metals nanoparticles,WO3 films,Photocurrent density
更新于2025-09-23 15:21:01
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Coagulation performance of cationic polyelectrolyte/TiO <sub/>2</sub> nanocomposites prepared under LED irradiation
摘要： A series of acrylic-based cationic polyelectrolyte nanocomposites including water-soluble monomers acrylamide (AAm) and 2-acryloyloxyethyltrimethylammonium chloride (DAC) with different mole percent of DAC (30, 40, and 45%) in feed were produced using TiO2 nanoparticles (0.018, 0.037, and 0.11 wt%) as photoinitiator in the aqueous solution of monomers and named as p(ADT)1–9. The LED light at 365 nm was used for photocatalysis activation of TiO2 nanoparticles. Structure and morphology of the synthetic polyelectrolyte were characterized by FT-IR, NMR, TGA, FESEM-EDX, and TEM. The other properties of synthetic polyelectrolyte such as molecular weight, viscosity, charge density, AAm/DAC molar ratio in copolymers, reactivity ratio values for the AAm and DAC monomers, and polymerization degree were measured. Furthermore, coagulation performance of these polyelectrolytes was investigated in soil suspension (1,000 ml, turbidity = 1,715 NTU). The prepared nanocomposites enhanced the coagulation of soil suspension up to 99.5% in low dosages. The best turbidity removal efficiencies (TRE) between 99.5–99.77% were achieved by p(ADT)3 conatining 30% DAC and 0.11 wt% TiO2. Decreasing the temperature from room temperature to 0°C led to an increase in TRE from 98 to 99.8%. Also, increasing the pH from 4 to 12 led to a decrease in TRE from 99.86 to 94%.
关键词： photopolymerization,cationic polyelectrolyte,coagulation performance,LED irradiation,TiO2 nanocomposites
更新于2025-09-23 15:19:57
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Facile fabrication of multi-scale microgroove textures on Ti-based surface by coupling the re-solidification bulges derived from nanosecond laser irradiation
摘要： A facile method is proposed to fabricate multi-scale microgroove textures (MGT) on Ti-based implant material. The effect of some primary parameters on the morphology of laser-irradiated surface is studied in detail. The results show that at the scanning speed of 42 mm/s, when the laser intensity is ≥4.0 J/cm2 typical microgroove structure with raised edges is produced by single-line scanning irradiation, and various MGT can be easily fabricated by multi-line scanning irradiation through properly adjusting the scanning interval in accordance with the feature size of microgroove structures. Meanwhile, it is firstly found that multi-scale MGT perpendicular to the scanning direction can be achieved by applying suitable high scanning speed with small scanning interval. Using a laser spot with the diameter of 20 μm, multi-scale MGT with various periods ranging from 15 (less than the laser spot diameter) to 35 μm are successfully fabricated on TA2 surfaces, and perpendicular ones with the same period of 21 μm but different ridge widths are also obtained. The aspect ratio of these MGT is > 1.5. Wettability measurements reveal that the water droplet on the produced multi-scale MGT owns anisotropic spreading speeds or spreading lengths. The energy dispersive spectroscopy tests indicate that their ridges are rich in titanium oxides which are good hemo-compatibility materials. The proposed method has a promising application for fabricating multi-scale MGT like those on natural vessel to the stent surface to improve its hemo-compatibility.
关键词： Microtexture,Functional surface,Anisotropic wettability,Laser irradiation,Microgroove
更新于2025-09-23 15:19:57