Effective synthesis of green nano‐sized ceramic pigments by co‐doping Zn²⁺, Cr³⁺ and Sm³⁺ into the cobalt‐aluminate

Abstract

A green nano‐sized ceramic pigment Co0.6Zn0.4Al0.8Cr1.2‐xSmxO4 has been successfully prepared by doping ions Zn2+, Cr3+, and Sm3+ into the crystalline CoAl2O4 spinel and using the complex‐gel method along with agar as complexing and combustion agent. The Infrared Spectroscopy, X‐ray diffraction, Thermo‐gravimeter, High resolution transmission electron microscopy, Automatic color reader, and UV Vis diffuse reflectance were applied to characterize the pigment power and its gel precursor. The results reveal that the introduction of Zn2+, Cr3+, and Sm3+ could change the occupation status of ions in the tetrahedral and octahedral framework of CoAl2O4 spinel, leading to the colorant variation of the blue cobalt pigment CoAl2O4, With increasing the content of Sm3+ ion, the reflection peak position of the pigments in visible spectrum appeared a red‐shift, ie the color transition from blue green to yellow green, and the average reflectivity in the violet region decreased to 13.31%, and the band gap energy also changed from 3.47 to 3.20 eV. This illustrates the better UV absorption of this green pigment and can be used as UV shielding material. With the hydrochloric acid or sodium hydroxide solution treatment, this pigment was found to be durable in chemical stability.

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

“…В соединениях переходных элементов насыщенную окраску имеют только те из них, которые окрашены в красно-желтые цвета. Это связано с тем, что полосы переноса заряда, характерные для ультрафиолетовой области, распространяются лишь на часть видимого спектра [12][13][14][15][16][17].…”

Synthesis of zeolite‐derived blue nanopigment and its modification for hydrophobic coating on ceramic tile

“…This unconventional approach to ceramic manufacturing presents notable advantages, as extensively expounded upon in the existing literature. [8][9][10][11] The introduction of transition metal cations into zeolite frameworks reveals a noteworthy aspect, imparting a distinct color that persists even after thermal treatment. This characteristic facilitates the direct fabrication of colored ceramics or powders that mimic ceramic pigments.…”

“…The application of high‐temperature firing to zeolitic powders induces structural alterations, yielding either amorphous or crystalline ceramics, contingent on their chemical composition. This unconventional approach to ceramic manufacturing presents notable advantages, as extensively expounded upon in the existing literature 8–11 …”

Color-controlled nonstoichiometric spinel-type cobalt gallate nanopigments prepared by supercritical hydrothermal synthesis

“…4 Therefore, color manipulation can be realized by doping with transition or rare-earth metal ions. [5][6][7] Other methods for color manipulation include the use of capping agents, 8 use of different polymorphs of the starting material, 9 and control of the calcination temperature. 10 A change in the calcination temperature was thought to realize different cationic configurations at tetrahedral and octahedral sites in the spinel structure, which could control the color of the products.…”