Flower-like morphology of blue and greenish-gray ZnCoxAl2-xO4 nanopigments

Wahba, Adel Maher; Imam, N.G.; Mohamed, Mohamed Bakr

doi:10.1016/j.molstruc.2015.10.052

Cited by 17 publications

(7 citation statements)

References 19 publications

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“…For all of the analysed powders, two absorption bands are observed at 662 and 572 cm 1 , corresponding to the stretching vibrations of the metal-oxygen bond; this result confirmed the spinel structure of Co3O4 [25][26][27]. Notably, it is extremely difficult to differentiate between the FTIR spectra of pure Co3O4 and of Co3O4 with CoO impurities [28].…”

Section: Study Of Starting Reagents: Co(no3)2•nh2osupporting

confidence: 58%

Synthesis of cobalt aluminate spinel by sol-gel process: Investigation of starting reagents and precursors obtained after pyrolysis

Jabbar

Lakhlifi

Ouatib

et al. 2021

Chemical Data Collections

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Section: Study Of Starting Reagents: Co(no3)2•nh2osupporting

confidence: 58%

Synthesis of cobalt aluminate spinel by sol-gel process: Investigation of starting reagents and precursors obtained after pyrolysis

Jabbar

Lakhlifi

Ouatib

et al. 2021

Chemical Data Collections

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“…Ali the diffraction peaks well matched with the standard JCPDS data for the direct spinel Co 2+ [Al� + ]O 4 (JCPDS file n ° 70-0753). The appearance of the reflec tion 331 at 49.3 ° (Figs.2 and 3) is characteristic of the blue spinel compound Co 2+ [Al� + ]O4[29]. The structural analysis by XRD re vealed that no effect of the complexing agent was observed for the samples obtained at a annealing temperature equal or superior to 900 °G.…”

mentioning

confidence: 85%

Structure, microstructure, optical and magnetic properties of cobalt aluminate nanopowders obtained by sol-gel process

Jabbar

Lakhlifi

Ouatib

et al. 2020

Journal of Non-Crystalline Solids

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The aim of this study was to detennine the effect of different complexing agents and of the annealing tem perature on the structural, morphological and optical properties of the synthesized precursors. Thus, cobalt aluminate nanoparticles were prepared by the sol-gel method using polyacrylic acid, glycine or citric acid as complexing agents. The synthesis performed at 500 °C for 5 hours led to dark green powders composed of solid solutions denoted Co 2+ [ Agci-x) Co�;i]O4 and of amorphous alumina (39.8wt%). Calcination at temperatures above 900 °C caused the powder colour to change from dark green to blue. A direct spinel structure Co 2+ [ Al� + ] 04 is all the more achieved as the annealing temperature is high. The powder obtained using polyacrylic acid as the complexing agent at 900 °C for 5 hours revealed the best morphology; it consisted of agglomerates of primary particles with a quasi-spherical shape and a size in the range 20-40 nm.

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“…Красный, коричневый и бурый цвета в основном определяются интенсивной полосой переноса заряда. Такая же окраска характерна для Fe 3 + с тетраэдрической координацией, хотя в этом случае она будет обусловлена d-d-переходом [27][28][29] [28][29][30][31][32][33]. Образцы, в которых ион кобальта связан с 4 лигандами, окрашены -в сине-фиолетовый цвет.…”

Section: результаты и обсуждениеunclassified

Spectrophotometric Color Determination Of Ceramic Pigments for Construction Ceramics And Regional Innovation System

2021

Chemistry and Chemical Engineering

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The purpose of this work is the spectrophotometric determination of the color of ceramic pigments for the development of technology for the production of high-quality ceramic paints of a wide color palette for decorating building ceramics, porcelain and faience products. In this regard, using the principles of heterovalent isomorphic substitution of atoms in crystals, the compositions of ceramic pigments were designed on the basis of the anorthite derivatives containing transition elements with the general formula Са1-хMexAl2+xSi2-xО8, where calcium and silicon ions were replaced by aluminum and transition element, Ме – Cо, Ni, Fe, Cr. The color characteristics were taken on the UV-2600 spectrophotometer with «UV Probe» software. Measurement of wavelengths was in the range of -220-1400 nm. For Fe3+ with tetrahedral coordination, the brown color is due to the d–d transition. The absorption wavelengths of the samples corresponded to 758-283 nm. Со2+ is characterized by a coordination number of 4, the wavelengths of the absorbed light are 1328, 776, 625, 551, and 408 nm. In this case, the brightness varies from 5 to 64%. The color of the samples is violet-blue. For the yellow-green complex [NiО6], the absorption bands are located at ⅄ = 894, 693, 622, 385. The absorption spectra of chromium-containing pigments are characterized by the presence of maxima in the region of 536, 408, 310 nm, which corresponds to the green region of the spectrum

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Flower-like morphology of blue and greenish-gray ZnCoxAl2-xO4 nanopigments

Cited by 17 publications

References 19 publications

Synthesis of cobalt aluminate spinel by sol-gel process: Investigation of starting reagents and precursors obtained after pyrolysis

Synthesis of cobalt aluminate spinel by sol-gel process: Investigation of starting reagents and precursors obtained after pyrolysis

Structure, microstructure, optical and magnetic properties of cobalt aluminate nanopowders obtained by sol-gel process

Spectrophotometric Color Determination Of Ceramic Pigments for Construction Ceramics And Regional Innovation System

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