Green inorganic pigment production with spinel structureCoCr2O4by solution combustion synthesis

Abstract

In this research, inorganic pigment with spinel structure CoCr 2 O 4 was synthesized by the solution combustion synthesis using glycine as fuel in an one-step. The powders as-prepared after combustion and then calcined at 700 °C during 6 hours, were characterized by the X-ray diffraction (XRD), and both samples showed the peaks corresponding to the expected spinel structure. which showed that the spinel structure was obtained in the combustion reaction.  Images of field emission scanning electron microscope (FE-SEM) showed the formation of porous and agglomeration of particles with, irregular shape. Finally, diffuse reflectance visible spectra were showed with an absorption band in the range of 570 nm -670 nm, which is due to electronic transitions corresponding to 4 A 2 (F) → 4 T 1 (P) when the cation of Co 2+ in tetrahedrical position and electronic transitions 4 A 2g → 4 T 2g of Cr 3+ in octaedrical positions. Color coordinates CIEL*a*b* correspond to a green color, which is consistent with the diffuse reflectance spectra.