Luminescence of Binary-Doped Silica Aerogel Powders: A Two-Step Sol-Gel Approach.

In this study, we report a novel synthesis of hydrophobic silica aerogel powder composites, functionalized and binary-doped with [Tb(phen)](NO) and [Eu(phen)](NO) nanocrystals, employing a two-step sol-gel methodology. The investigation delves into the structural elucidation, optical properties and thermal conductivity of these functionalized Tb(III)-Eu(III) composites. Our analysis includes diffuse reflectance spectra and excitation and luminescence spectra, highlighting the quantum yields of composites with varying chemical compositions.

Silica Gels Doped with Gold Nanoparticles: Preparation, Structure and Optical Properties.

A novel, one-pot sol-gel preparation scheme leading to reproducible incorporation of 20-40 nm sized gold nanoparticles (AuNPs) in SiO gels is developed based on in situ reduction during gelation using chloroauric acid and ascorbic acid. Variation in the preparation conditions affects the chemical composition, optical properties and size distribution of the AuNPs incorporated in the silica gels. Different organic dopants, i.

The Influence of the Precursor's Nature and Drying Conditions on the Structure, Morphology, and Thermal Properties of TiO Aerogels.

A cost-effective solution for the synthesis of high-porosity TiO aerogels, which can be used as a mesoporous perovskite network charge-carrier material during the manufacture of solar cells, is described. The effects of the synthesis parameters (precursor (titanium (IV) isopropoxide (TIP) and tetrabutyl orthotitanate (TBOT)), additional solvent exchange (n-hexane (nH), cyclohexane (CH), and diethyl ether (DE)), subcritical drying (800 mbar vacuum, 70 °C, 8 h), aging, and calcination on the aerogel's structure have been investigated. Methods of XRD, FT-IR, BET, Raman, STA, SEM, UV-vis, and thermal conductivity measurements were applied to find out the relation between the synthesis conditions and the properties of the synthesized aerogels.

Effect of Precursor Nature and Sol-Gel Synthesis Conditions on TiO Aerogel's Structure.

The aim of this investigation was to synthesize high porosity TiO aerogel by applying sol-gel and subcritical drying methods and to identify the influence of reagent's nature and synthesis conditions on their structural and optical properties. Methods of XRD, FT-IR, BET, STA, SEM, and UV-vis were applied to investigate and compare the properties of synthesized TiO aerogels and to determine the most effective synthesis route. The structural parameters of the synthesized materials can be varied by changing the precursor type (titanium (IV), isopropoxide (TIP), or tetrabutylorthotitanate (TBOT)) and the nature of the solvent used for additional exchange (-hexane (nH), cyclohexane (CH), or diethyl ether (DE)).

Temperature dependent optical spectroscopy: A study of holmium diphenanthroline nitrate in DMF.

A detailed spectroscopic study of the optical properties of Ho(phen)(NO) complex is presented. The substance is characterized by UV/Vis spectroscopy, IR - spectroscopy, chemical analysis and X - Ray diffraction. Temperature dependent absorption spectra of Ho(phen)(NO) in DMF are discussed.

DFT modeling, UV-Vis and IR spectroscopic study of acetylacetone-modified zirconia sol-gel materials.

Theoretical and spectroscopic studies of a series of monomeric and dimeric complexes formed through the modification of a zirconium butoxide precursor with acetylacetone and subsequent hydrolysis and/or condensation have been performed by applying DFT/B3LYP/6-31++G(d) and highly accurate RI-ADC(2) methods as well as IR and UV-Vis transmittance and diffuse reflectance spectroscopies. Based on DFT model calculations and simulated and experimental UV-Vis and IR spectra of all the studied structures, the most probable building units of the Zr(IV)-AcAc gel were predicted: the dimeric double hydroxo-bridged complex Zr(2)(AcAc)(2)(OH)(4)(OH)(2br) 9 and the monooxo-bridged complex Zr(2)(AcAc)(2)(OH)(4)O(br)·2H(2)O 12. In both structures, the two AcAc ligands are coordinated to one Zr atom.