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Computational Chemistry Meets Experiments for Explaining the Geometry, Electronic Structure, and Optical Properties of Ca <sub/>10</sub> V <sub/>6</sub> O <sub/>25</sub>
摘要： In this paper, we present a combined experimental and theoretical study to disclose, for the first time, the structural, electronic, and optical properties of Ca10V6O25 crystals. The microwave-assisted hydrothermal (MAH) method has been employed to synthesize these crystals with different morphologies, within a short reaction time at 120 °C. First-principle quantum mechanical calculations have been performed at the density functional theory level to obtain the geometry and electronic properties of Ca10V6O25 crystal in the fundamental and excited electronic states (singlet and triplet). These results, combined with the measurements of X-ray diffraction (XRD) and Rietveld refinements, confirm that the building blocks lattice of the Ca10V6O25 crystals consist of three types of distorted 6-fold coordination [CaO6] clusters: octahedral, prism and pentagonal pyramidal, and distorted tetrahedral [VO4] clusters. Theoretical and experimental results on the structure and vibrational frequencies are in agreement. Thus, it was possible to assign the Raman modes for the Ca10V6O25 superstructure, which will allow us to show the structure of the unit cell of the material, as well as the coordination of the Ca and V atoms. This also allowed us to understand the charge transfer process that happens in the singlet state (s) and the excited states, singlet (s*) and triplet (t*), generating the photoluminescence emissions of the Ca10V6O25 crystals.
关键词： structural properties,electronic properties,Ca10V6O25,microwave-assisted hydrothermal method,photoluminescence,optical properties
更新于2025-09-10 09:29:36
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Modification of P25 titania in presence of hydrazine for <i>Staphylococcus aureus</i> inactivation
摘要： Titania and its polymorphs are one of the most studied semiconductor photocatalyst. Herein, the P25 titania was used as a precursor to modify the phase and structure with microwave assisted hydrothermal and sonochemical methods in presence of alkaline hydrazine. The outcome results show the cotton ball structure titanate composite phases (nanotubes, nanosheets and nanoparticles) and monoclinic titanate phase (TiO2-B) with microwave assisted hydrothermal method and sonochemical method, respectively. The nitrogen doping was confirmed by FTIR and DRS in modified TiO2. And some visible light absorption was observed in modified TiO2 due to the nitrogen doping. The composite phase titanate having cotton ball structure was found to be efficient for methicillin-resistant superbug Staphylococcus aureus (MRSA) inactivation. Herein, we also reported the submicron TiO2-B sword like morphology fabricated by sonochemical method for the first time in presence of alkaline hydrazine.
关键词： Bacterial inactivation,Titania,Sonochemical,Microwave assisted hydrothermal
更新于2025-09-10 09:29:36
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Multi-mode photocatalytic performances of CdS QDs modified CdIn2S4/CdWO4 nanocomposites with high electron transfer ability
摘要： In general, quantum dots have the property of generating a plurality of charge carriers using hot electrons or using a single high-energy photon to improve the photocatalytic properties of the material. In this paper, CdS QDs@CdIn2S4/CdWO4 modified by CdS QDs was synthesized by the microwave-assisted hydrothermal method, and its composition, crystal structure, morphology, and surface physicochemical properties were well characterized. Electron microscopy results showed that CdS QDs@CdIn2S4/CdWO4 composite material exhibited a sheet structure with a length of ca. 350 nm and a width of ca. 50 nm, and CdS QDs uniformly distributes with a diameter of about 5 nm on the sheet structure. UV-visible diffuse reflectance tests showed that the combination of CdS QDs and CdIn2S4 can extend the light absorption range of CdWO4 to the visible region. Photoluminescence spectroscopy confirmed that CdS QDs had efficient electron transport capabilities. The multi-mode photocatalytic activity of CdS QDs@CdIn2S4/CdWO4 showed an excellent ability to degrade organic pollutants. Under the conditions of no co-catalyst and Na2S-Na2SO3 as the sacrificial agent, the hydrogen production of CdS QDs@CdIn2S4/CdWO4 can reach 221.3 μmol g?1 when exposed to visible light (λ > 420 nm) for 8 h.
关键词： CdS QDs,Quantum dots,Microwave-assisted hydrothermal method,CdWO4,Multimode photocatalysis,H2 evolution,CdIn2S4
更新于2025-09-10 09:29:36