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Recent development on modification of synthesized barium titanate (BaTiO3) and polymer/BaTiO3 dielectric composites
摘要： In order to fabricate barium titanate (BaTiO3) particles with high purity, small particle size and narrow distribution of particle size, the synthesis methods and doping elements should be properly selected. Compared to polar polymers, non-polar polymers have advantages on the fabrication of miniaturized and lightweight electronic devices, due to excellent process-ability and little endogenous heat generated in the electric field. To avoid the aggregation of BaTiO3 particles in polymer matrix, several nanometer thick organic coating on the BaTiO3 surface is needed. What’s more, the alignment of BaTiO3 and hybrid use of fillers can further improve the dielectric properties of polymer/BaTiO3 composites.
关键词： Barium titanate,Synthesis methods,Dielectric properties,Surface modification,Polymer composites
更新于2025-09-04 15:30:14
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Molecular Doping of Electrochemically Prepared Triazine-Based Carbon Nitride by 2,4,6-Triaminopyrimidine for Improved Photocatalytic Properties
摘要： Copolymerization of melamine with 2,4,6-triaminopyrimidine (TAP) in an electrochemically induced polymerization process leads to the formation of molecular doped poly(triazine imide) (PTI). The polymerization is based on the electrolysis of water and evolving radicals during this process. The incorporation of TAP is shown by techniques such as elemental analysis, Fourier transform infrared and NMR spectroscopies, and powder X-ray diffraction, and it is shown that the carbon content can be tuned by the variation of the molar ratio of the two precursors. This incorporation of TAP directly influences the electronic structure of PTI and as a result, a red shift can be observed in UV?vis spectroscopy. The smaller band gap and the increased absorption in the visible range lead to improved photocatalytic properties. In dye degradation experiments, it was possible to observe an increase of the rate of the degradation of methylene blue by a factor of 4 in comparison to undoped PTI or 7 if compared to melon.
关键词： 2,4,6-triaminopyrimidine,photocatalysis,electrochemical synthesis,molecular doping,poly(triazine imide)
更新于2025-09-04 15:30:14
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Direct synthesis of MoS <sub/>2</sub> or MoO <sub/>3</sub><i>via</i> thermolysis of a dialkyl dithiocarbamato molybdenum( <scp>iv</scp> ) complex
摘要： Direct synthesis of either 2H-MoS2 or a-MoO3 is made possible by thermolysis of the same single source precursor in either argon or air at moderate temperatures.
关键词： direct synthesis,thermolysis,MoS2,MoO3,single source precursor
更新于2025-09-04 15:30:14
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Bi <sub/>5</sub> O <sub/>7</sub> NO <sub/>3</sub> and Ag/Bi <sub/>5</sub> O <sub/>7</sub> NO <sub/>3</sub> composites: one-step solution combustion synthesis, characterization and photocatalytic properties
摘要： In the present study, Bi5O7NO3 and Ag/Bi5O7NO3 composites, as novel efficient photocatalysts, were synthesized via a one-step solution combustion synthesis (SCS) using bismuth nitrate (Bi(NO3)3·5H2O) as an oxidant, tartaric acid (C4H6O6) as a fuel, and silver nitrate (AgNO3) as an Ag source. The amount of Ag in the composite was tailored by varying the AgNO3 content during the SCS process. The orthorhombic Bi5O7NO3 crystal structure was confirmed by XRD, FT-IR and XPS. It was found by EDS and TEM that in the Ag-containing composite, Ag was uniformly distributed on the Bi5O7NO3 matrix. The Ag decoration improved the Bi5O7NO3 photocatalytic efficiency for methyl orange (MO) degradation, likely owing to the relatively low recombination rates of electrons and holes. The 5 mol% Ag/Bi5O7NO3 composite exhibited the best photocatalytic performance (95% in 60 min), which was 1.5 times higher compared to that of pure Bi5O7NO3. In addition, a mechanism of the photocatalytic MO degradation reaction was proposed, which the reactive species O2? played an important role in degrading pollutants.
关键词： Bi5O7NO3,methyl orange degradation,Ag/Bi5O7NO3 composites,solution combustion synthesis,photocatalytic properties
更新于2025-09-04 15:30:14
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Fabricated Pt–C-Mesoporous TiO <sub/>2</sub> for the Photoreduction of CO <sub/>2</sub> Into Renewable Hydrocarbon Fuels
摘要： Various Pt-supported mesoporous TiO2 catalysts (0.5–1.5 wt%) were prepared using a hydrothermal approach. The photocatalytic activity of the catalysts in CO2 photoreduction was tested in the gaseous phase while using H2O as an electron donor and a Hg lamp as the UV light source. The results showed that the Pt–C-meso-TiO2 has a large surface area, which can increase the CO2 absorption capacity. The CH4 production of Pt–C-meso-TiO2 increased while the charge separation increased. The amount of Pt loaded onto TiO2 was optimized, with 1.0 wt% showing the highest photocatalytic activity (the CH4 production rate of 1.0 wt% Pt–C-meso-TiO2 reached 20.23 μmol · h?1g?1 under the UV light source. Moreover, 1.0 wt% Pt–C-meso-TiO2 can be used repeatedly with a negligible loss of photocatalytic activity after 60 days. Furthermore, a mechanism of the photoreduction of CO2 was proposed. Therefore, Pt–C-meso-TiO2 is an efficient photocatalyst for the photoreduction of CO2 to CH4.
关键词： Semiconductors,Electron Microscopy,Chemical Synthesis,Electrochemical Properties
更新于2025-09-04 15:30:14
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A Study on Photocatalytic Behaviors of Activated Carbon Fibers Impregnated with N-Doped Titania
摘要： Activated carbon ?bers (ACFs) impregnated with N-doped titania were prepared via the sol–gel method and sonochemical synthesis. The photocatalytic behavior of rhodamine B showed that N-doped TiO2/ACF nanocomposites exhibited enhanced photocatalytic activity. This result could be attributed to the synergistic effect between the high adsorption capacity of ACF and the visible light photocatalytic activity of N-doped TiO2. In particular, the N-doped TiO2/ACF nanocomposite that was sonicated four times had the highest photocatalytic ef?ciency and degradation rate, owing to the optimal N-doped TiO2 loading and nanocomposite pore structure.
关键词： N-doped TiO2,Sonochemical Synthesis,Activated Carbon Fibers,Photodegradation
更新于2025-09-04 15:30:14
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Phyto-Mediated Photo Catalysed Green Synthesis of Silver Nanoparticles Using Durio Zibethinus Seed Extract: Antimicrobial and Cytotoxic Activity and Photocatalytic Applications
摘要： In the present study, we have developed a green approach for the synthesis of silver nanoparticles (DSAgNPs) using aqueous extract of Durio zibethinus seed and determined its antibacterial, photocatalytic and cytotoxic effects. Surface plasmon resonance confirmed the formation of DSAgNPs with a maximum absorbance (λmax) of 420 nm. SEM and TEM images revealed DSAgNPs were spherical and rod shaped, with a size range of 20 nm and 75 nm. The zeta potential was found to be ?15.41 mV. XRD and EDX analyses confirmed the nature and presence of Ag and AgCl. DSAgNPs showed considerable antibacterial activity, exhibited better cytotoxicity against brine shrimp, and shown better photocatalytic activity against methylene blue. Based on the present research work, it can be concluded that DSAgNPs could be used in the field of water treatment, pharmaceuticals, biomedicine, biosensor and nanotechnology in near future.
关键词： antibacterial,silver,Durio zibethinus seed,green synthesis,cytotoxicity,nanoparticles
更新于2025-09-04 15:30:14
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Surfactant Free Hydrothermal Synthesis of Zn <sub/>2</sub> SnO <sub/>4</sub> Nanoparticles and Their Functional Properties
摘要： A simple, low temperature, cost effective, surfactant free and scalable synthesis of technologically important Zn2SnO4 (ZTO) nanoparticles with controllable size and shape has been developed. X-ray diffraction (XRD), transmission electron microscopy (TEM) and high-resolution transmission electron microscopy (HRTEM) of the synthesized ZTO nanoparticles revealed the formation of highly pure crystalline ZTO phase with the spinel-like structure. The Raman spectrum of the sample was dominated by the A1g vibration mode of pure ZTO phase. From UV–Vis absorption measurements, a band gap (Eg) of 3.78 eV was determined. The photocatalytic activity of the ZTO nanoparticles was evaluated for the photodegradation of methylene blue (MB) under UV-Vis light irradiation. The ZTO-assisted photocatalytic degradation of MB is complete in 25 minutes indicating good photocatalytic activity of ZTO. Mass spectrometric (MS) analysis of degradation intermediates isolated at regular time intervals reveals the presence of azure A, azure B and thionin which are demethylated products of the MB, indicating that the degradation is initiated by demethylation of the molecule.
关键词： Nanoparticles,Photocatalysis,Zn2SnO4,Transmission electron microscopy,Hydrothermal Synthesis
更新于2025-09-04 15:30:14
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Turning ESIPT-Based triazine fluorophores into dual emitters: From theory to experiment
摘要： In an effort to design new dyes presenting multiple fluorescence bands, we use theoretical chemistry to guide the synthesis of new triazine structures undergoing excited-state intramolecular proton transfer (ESIPT). Starting with experimentally-known compounds showing only emission from the keto tautomer, we model several chemically-achievable substitutions aiming to sufficiently frustrate the ESIPT process by stabilising the enol structure in the electronic excited state. In a second step, some of the proposed dyes are synthesised. It turns out that the emergence of an emission band due to the enol confirms the theoretical prediction, though the observed quantum yields in solution are small as a consequence of the selection of methoxy substituents. The quantum yields are strongly improved when going to the solid-state as a result of the impeded rotations.
关键词： dual emitters,theoretical chemistry,synthesis,triazine fluorophores,ESIPT
更新于2025-09-04 15:30:14
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Synthesis and characterization of luminescent metal–organic frameworks for the selective recognition of Cu2+ cation and Tryptophan
摘要： Three metal-organic frameworks (MOFs), namely, [Mn(CPP)2(H2O)]n (I), [Cd(CPP)2(H2O)]n (II) and {[Zn2(CPP)2(CO3)]·(ClO4)·(H2O)2}n (III) (HCPP = 4'-(4-(4-carboxylphenoxy)-2,2':60,20-terpyridine), were successfully achieved under hydrothermal conditions. The as-synthesized coordination polymers have been characterized by IR spectroscopy, elemental analyses and single crystal X-ray diffraction. Single-crystal X-ray diffraction analyses indicate that compounds ⅠⅠ and ⅡⅡ display isomorphous and isostructural, in which the central metal ions present distorted octahedral configurations. ⅠⅠ and ⅡⅡ feature fascinating 3D frameworks based on p/p and CeH/p interactions between the pyridine rings ligands, while compound ⅢⅢ possesses a 3D net interlinked via C-H/p interactions appertaining CPP ligands. In their 3D frameworks, the {MnN3O3}, {CdN3O3} and {ZnO2N3}e{ZnO2N3} building units are observed, respectively. Luminescent properties of coordination polymer ⅡⅡ and ⅢⅢ demonstrate that they may be acted as fluorescent sensors toward Cu2+ cation and Tryptophan, respectively. Furthermore, investigations on magnetic property reveal that coordination polymer ⅠⅠ presents antiferromagnetic coupling.
关键词： Magnetic analysis,Luminescent recognition,Transition metal ions,Hydrothermal synthesis,Metal organic frameworks
更新于2025-09-04 15:30:14