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Preparation and luminescent properties of mesoporous (SBA-15)-Eu2O3 nano materials
摘要： The CH3-(SBA-15) and (SBA-15)-Eu2O3 host-gust nanocomposite materials were synthesized by post-synthesis method, ultrasonic synthesis method (UM) and ultrasonic assisted synthesis methods (UAM). The X-ray diffraction (XRD), infrared spectroscopy (IR), scanning electron microscopy (SEM), transmission electron microscope (TEM) analysis and nitrogen adsorption-desorption method were used to observe the structure, the surface morphology and the chemical composites of the prepared products. The luminescent properties, and the luminescent intensity of the samples were studied by excitation and emission spectra. The results showed that, for the (SBA-15)-Eu2O3 composite materials, the hexagonal pore structure of the SBA-15 molecular sieve was maintained. The luminescent intensity of the UM sample was about 6 times higher than that of the mechanical mixture of SBA-15 and nano-Eu2O3 (5 wt %). The excitation spectrum intensity was 2 times higher than that of the mechanical mixture.
关键词： (SBA-15)-Eu2O3,Luminescence,SBA-15 molecular sieve,Trimethyl chlorosilane,Host-gust nanocomposite material
更新于2025-09-23 15:21:21
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Photo-induced generation of size controlled Au nanoparticles on pure siliceous ordered mesoporous silica for catalytic applications
摘要： A versatile in situ photochemical reduction approach was used to generate a composite of gold nanoparticles and pure siliceous SBA-15 silica support with regular mesopores. The mesoporous silica support was first synthesized and, after calcination, was suspended in a solution of gold bromide (EtOH or H2O) containing a free radical generator activated by UV irradiation and used for the photochemical reduction of gold precursor. The influence of gold precursor concentration, light intensity and nature of the solvents on the formation and properties of gold nanoparticles (size, dispersion, stability) on the mesoporous SBA-15 support have been studied with the aim of optimizing the dispersion of the gold nanoparticles in the mesoporous network and their chemical stability. The catalytic activity of the resulting AuNPs@SBA-15 nanocomposite was successfully evaluated for the oxidation of benzyl alcohol reaction in liquid-phase.
关键词： Benzyl alcohol,Photoreduction,Gold nanoparticles,Mesoporous silica,SBA-15,Oxidation
更新于2025-09-12 10:27:22
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Dopant-Free Squaraine-Based Polymeric Hole-Transporting Materials with Comprehensive Passivation Effects for Efficient All-Inorganic Perovskite Solar Cells
摘要： Quantum-dot (QD) white light-emitting diodes (LEDs) are promising for illumination and display applications due to their excellent color quality. Although they have a high quantum yield close to unity, the reabsorption of QD light leads to high conversion loss, significantly reducing the luminous efficacy and stability of QD white LEDs. In this report, SBA-15 mesoporous particles (MPs) with two-dimensional hexagonal pore structures (2D-HPS) are utilized to largely enhance the luminous efficacy and color-conversion efficiency of QD white LEDs in excess of 50%. The reduction in conversion loss also helps QD white LEDs to achieve a lifetime 1.9 times longer than that of LEDs using QD-only composites at harsh aging conditions. Simulation and testing results suggest that the waveguide effect of 2D-HPS helps in reducing the reabsorption loss by constraining the QD light inside the wall of 2D-HPS, decreasing the probability of being captured by QDs inside the hole of 2D-HPS. As such, materials and mechanisms like SBA-15 MPs with 2D-HPS could provide a new path to improve the photon management of QD light, comprehensively enhancing the performances of QD white LEDs.
关键词： stability,two-dimensional hexagonal pore structure,reabsorption,luminous efficacy,SBA-15 mesoporous particle,quantum-dot white light-emitting diode
更新于2025-09-11 14:15:04
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Synthesis and Morphological Control of Mesoporous SiO2 with Cotton as Bio-Template
摘要： Mesoporous SiO2 with special short open axis-like morphology was successfully fabricated by using cotton fibers as bio-templates. Mesostructure and morphology of the samples were systematically studied by changing the cotton/SiO2 weight ratio and hydrothermal treating temperature. Textural property and morphology of the obtained mesoporous SiO2 were characterized by the combination of X-ray diffraction, N2 adsorption-desorption experiments and scanning electron microscope. Finally, batch adsorption of methylene blue was performed to detect the adsorption capacity of the cotton co-templated materials.
关键词： Cotton,SBA-15,Morphology control,Bio-template
更新于2025-09-09 09:28:46
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Synthesis g-C <sub/>3</sub> N <sub/>4</sub> of high specific surface area by precursor pretreatment strategy with SBA-15 as a template and their photocatalytic activity toward degradation of rhodamine B
摘要： Using SBA-15 as a template, high surface area porous graphitic carbon nitrides (g-C3N4) were successfully synthesized by pretreating melamine using hydrochloric acid, and fully characterized by Fourier-Transform infrared (FT-IR), X-ray diffraction (XRD), scanning electron micrographs (SEM), N2 adsorption-desorption, ultraviolet-visible (UV-Vis) spectroscopy, photoluminescence (PL) spectrum. The results of these analyses indicated that the g-C3N4 synthesized from HCl-pretreated melamine with SBA-15 as a template has enhanced specific surface area and increased the separation rate of the photogenerated electrons and holes compared with bulk g-C3N4, but didn’t change the structure of bulk g-C3N4. The photocatalytic activity of samples was evaluated by the degradation of rhodamine B (RhB) under xenon lamp. The results indicated that the activity was improved significantly with the increase of specific surface area. The rate constant for CN-3（ HCl pretreatment melamine precursor and SBA-15 as a template） was 13 times as high as g-C3N4. Furthermore, the CN-3 catalyst exhibited outstanding structural and catalytic stability.
关键词： precursor pretreatment strategy,SBA-15 template,g-C3N4,Degradation of RhB,high surface area
更新于2025-09-04 15:30:14