scholarly journals Investigation of Structural and Luminescent Properties of Sol-Gel-Derived Cr‑Substituted Mg3Al1−xCrx Layered Double Hydroxides

Molecules ◽  
2021 ◽  
Vol 26 (7) ◽  
pp. 1848
Author(s):  
Ligita Valeikiene ◽  
Inga Grigoraviciute-Puroniene ◽  
Arturas Katelnikovas ◽  
Aleksej Zarkov ◽  
Aivaras Kareiva
Keyword(s):  
Layered Double Hydroxides ◽  
Single Phase ◽  
Sol Gel ◽  
Visible Spectrum ◽  
Luminescent Properties ◽  
Ion Concentration ◽  
Substitution Level ◽  
Characteristic Emission ◽  
Chromium Substitution ◽  
Double Hydroxides

In the present work, Cr-substituted Mg3Al1−xCrx layered double hydroxides (LDHs) were synthesised through the phase conversion of sol-gel-derived mixed-metal oxides in an aqueous medium. The chromium substitution level in the range of 1 to 25 mol% was investigated. It was demonstrated that all synthesised specimens were single-phase LDHs. The results of elemental analysis confirmed that the suggested synthetic sol-gel chemistry approach is suitable for the preparation of LDHs with a highly controllable chemical composition. The surface microstructure of sol-gel-derived Mg3Al1−xCrx LDHs does not depend on the chromium substitution level. The formation of plate-like agglomerated particles, which consist of hexagonally shaped nanocrystallites varying in size from approximately 200 to 300 nm, was observed. Optical properties of the synthesised Mg3Al1−xCrx LDHs were investigated by means of photoluminescence. All Cr-containing powders exhibited characteristic emission in the red region of the visible spectrum. The strongest emission was observed for the sample doped with 5 mol% Cr3+ ions. However, the emission intensity of samples doped with 1–10 mol% Cr3+ ions was relatively similar. A further increase in the Cr3+ ion concentration to 25 mol% resulted in severe concentration quenching.

scholarly journals Sol–Gel Synthesis and Characterization of Coatings of Mg-Al Layered Double Hydroxides

Materials ◽  
2019 ◽  
Vol 12 (22) ◽  
pp. 3738 ◽  
Author(s):  
A. Smalenskaite ◽  
M. M. Kaba ◽  
I. Grigoraviciute-Puroniene ◽  
L. Mikoliunaite ◽  
A. Zarkov ◽  
...  
Keyword(s):  
Thin Films ◽  
Layered Double Hydroxides ◽  
Sol Gel ◽  
Xrd Analysis ◽  
Dip Coating ◽  
Dipping Process ◽  
Synthetic Approaches ◽  
Sol Gel Synthesis ◽  
Double Hydroxides ◽  
Steel Substrates

In this study, new synthetic approaches for the preparation of thin films of Mg-Al layered double hydroxides (LDHs) have been developed. The LDHs were fabricated by reconstruction of mixed-metal oxides (MMOs) in deionized water. The MMOs were obtained by calcination of the precursor gels. Thin films of sol–gel-derived Mg-Al LDHs were deposited on silicon and stainless-steel substrates using the dip-coating technique by a single dipping process, and the deposited film was dried before the new layer was added. Each layer in the preparation of the Mg-Al LDH multilayers was separately annealed at 70 °C or 300 °C in air. Fabricated Mg-Al LDH coatings were characterized by X-ray diffraction (XRD) analysis, scanning electron microscopy (SEM), and atomic force microscopy (AFM). It was discovered that the diffraction lines of Mg3Al LDH thin films are sharper and more intensive in the sample obtained on the silicon substrate, confirming a higher crystallinity of synthesized Mg3Al LDH. However, in both cases the single-phase crystalline Mg-Al LDHs have formed. To enhance the sol–gel processing, the viscosity of the precursor gel was increased by adding polyvinyl alcohol (PVA) solution. The LDH coatings could be used to protect different substrates from corrosion, as catalyst supports, and as drug-delivery systems in medicine.

Synthesis of Zn0.2Ca0.8TiO3:0.1Pr3+ by Sol-Gel and its Luminescence Characterization

2013 ◽  
Vol 750-752 ◽  
pp. 877-880
Author(s):  
Yi Shen ◽  
Li Ying Han ◽  
Lu Yao Hou
Keyword(s):  
Treatment Process ◽  
Sintering Temperature ◽  
Sol Gel ◽  
Ultra Violet ◽  
Luminescent Properties ◽  
Luminescent Materials ◽  
Excitation Spectra ◽  
Surface Appearance ◽  
Calcination Temperatures ◽  
Characteristic Emission

The Zn0.2Ca0.8TiO3:0.1Pr3+ luminescent materials were prepared by sol-gel technology. The phase transformation of gel was studied by TG-DTA and XRD in heat treatment process. The luminescent properties of phosphor in different calcination temperatures were determined by fluorescence spectrophotometer, and then the best sintering temperature was confirmed. The luminescent properties of phosphor was obtained through the emission/ excitation spectra. The surface appearance measured with SEM. The results showed that the nanoZn0.2Ca0.8TiO3:0.1Pr3+ phosphor could be obtained by sol-gel, sintering at 900°C. It sent out red fluorescent under the Ultra Violet. This characteristic emission peak at 614nm is associated with the typical 1D23H4 transition of Pr3+ion.

Synthesis and characterization of Zn/Al and Pt/Zn/Al layered double hydroxides obtained by the sol–gel method

2005 ◽  
Vol 80 (1-3) ◽  
pp. 213-220 ◽  
Author(s):  
Didier Tichit ◽  
Olivier Lorret ◽  
Bernard Coq ◽  
Federica Prinetto ◽  
Giovanna Ghiotti
Keyword(s):  
Layered Double Hydroxides ◽  
Sol Gel ◽  
Synthesis And Characterization ◽  
Gel Method ◽  
Sol Gel Method ◽  
Double Hydroxides

scholarly journals Undoped and Eu3+ Doped Magnesium-Aluminium Layered Double Hydroxides: Peculiarities of Intercalation of Organic Anions and Investigation of Luminescence Properties

Materials ◽  
2019 ◽  
Vol 12 (5) ◽  
pp. 736 ◽  
Author(s):  
Aurelija Smalenskaite ◽  
Lina Pavasaryte ◽  
Thomas Yang ◽  
Aivaras Kareiva
Keyword(s):  
Layered Double Hydroxides ◽  
Organic Anion ◽  
Sol Gel ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Organic Guests ◽  
Double Hydroxides ◽  
Scanning Electron

The Mg3/Al and Mg3/Al0.99Eu0.01 layered double hydroxides (LDHs) were fabricated using a sol-gel chemistry approach and intercalated with different anions through ion exchange procedure. The influence of the origin of organic anion (oxalate, laurate, malonate, succinate, tartrate, benzoate, 1,3,5-benzentricarboxylate (BTC), 4-methylbenzoate (MB), 4-dimethylaminobenzoate (DMB) and 4-biphenylacetonate (BPhAc)) on the evolution of the chemical composition of the inorganic-organic LDHs system has been investigated. The obtained results indicated that the type and arrangement of organic guests between layers of the LDHs influence Eu3+ luminescence in the synthesized different hybrid inorganic–organic matrixes. For the characterization of synthesis products X-ray diffraction (XRD) analysis, infrared (FTIR) spectroscopy, fluorescence spectroscopy (FLS), and scanning electron microscopy (SEM), were used.

Proposed General Sol−Gel Method to Prepare Multimetallic Layered Double Hydroxides: Synthesis, Characterization, and Envisaged Application

2009 ◽  
Vol 21 (24) ◽  
pp. 5826-5835 ◽  
Author(s):  
Julia Prince ◽  
Ascencion Montoya ◽  
Gerardo Ferrat ◽  
Jaime S. Valente
Keyword(s):  
Layered Double Hydroxides ◽  
Sol Gel ◽  
Gel Method ◽  
Sol Gel Method ◽  
Double Hydroxides
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