The Effect of Ni2+ Ions Substitution on Structural, Morphological, and Optical Properties in CoCr2O4 Matrix as Pigments in Ceramic Glazes

Abstract

The structural, morphological, and optical properties of Ni2+ ions substitution in CoCr2O4 matrix as ceramic pigments were investigated. The thermal decomposition of the dried gel was performed aiming to understand the mass changes during annealing. The X-ray diffraction (XRD) studies reveal a spinel-type Face–Centered Cubic structure and a secondary Cr2O3 phase when x ≤ 0.75 and a Body–Centered Tetragonal structure when x = 1. Fourier Transform Infrared Spectroscopy (FT–IR) indicated two strong absorption bands corresponding to the metal–oxygen stretching from tetrahedral and octahedral sites, characteristic of spinel structure. Ultraviolet–Visible (UV–Vis) spectra exhibited the electronic transitions of the Cr2+ Cr3+ and Ni2+ ions. From the UV–Vis data, the CIE color coordinates, (x, y) of the pigments were evaluated. The morphology was examined by Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) showing the agglomeration behavior of the particles. The stability, coloring properties and potential ceramic applications of studied pigments were tested by their incorporation in matte and glossy tile glazes followed by the application of obtained glazes on ceramic tiles. This study highlights the change in pigment color (from turquoise to a yellowish green) with Ni2+ ions substitution in the CoCr2O4 spinel matrix.

Synthesis, Physicochemical Characterization and Applications of Advanced Nanomaterials

“…The structural characterization is consistent with the Ni 2+ substitution of Co 2+ ions, thereby a decrease of unit cell parameter and the unit cell volume was observed with an increase of x. The increase of Ni 2+ substitution in the matrix has a pronounced increase in the size of the crystallites from 39.9 nm (for x = 0) to 99.42 nm (for x = 0.75) [ 5 ]. FT–IR indicated two strong absorption bands corresponding to the metal–oxygen stretching from tetrahedral and octahedral sites, characteristic of a spinel structure.…”

“…Adjusting the nickel content in the CoCr 2 O 4 matrix, the color of the pigment can be easily controlled. Lighter shades of ceramic glazes can be obtained when embedding in glossy glaze and darker shades can be obtained when embedding in a matte glaze, confirming the spinels’ applicability as pigments in the ceramic tile industry [ 5 ]. SEM and TEM microscopy evidenced the powder morphology and the tendency of nanoparticles to agglomerate.…”

“…In this Special Issue, Goga et al [ 5 ], focused on the Ni substitution of cobalt ions in a Co x Cr 2 O 4 matrix (x = 0, 0.25, 0.5, 0.75, and 1.00) by using a sol–gel synthesis route, was performed. The X-ray diffraction (XRD) studies reveal a spinel-type Face–Centered Cubic structure and a secondary Cr 2 O 3 phase when x ≤ 0.75 and a Body–Centered Tetragonal structure when x = 1.…”

“…The elemental EDX distribution of Ni Kα1 in the glossy ceramic tile confirms the homogeneous and uniform pigment distribution in the glaze after firing. All the samples present distinct stable colors and good structural and morphological properties that recommend them to be used as ceramic pigments [ 5 ].…”

Unraveling the Effect of the Chemical and Structural Composition of ZnxNi1−xFe2O4 on the Electron Transfer at the Electrochemical Interface

“…Following the literature, [ 51 ] we assigned the bands at 485 and 571 nm to 3 A 2g ( F ) → 3 T 2g ( F ) transitions of octahedral Ni(II) ions, whereas the bands at 635 and 750 nm are assigned to 3 T 1 ( F ) → 3 T 1g ( P ) transition of tetrahedrally coordinated Ni(II) ions [ 52 ] and the 3 A 2 ( F ) → 3 T 1 ( F ) transitions as the d – d transition of Ni(II) ions in a tetrahedral environment. [ 53 ] This is evident from the fact that Ni ferrite is an inverse spinel material with Ni(II) sharing the octahedral and tetrahedral sites with Fe(III). [ 24,25 ]…”