Optics and Photonics Society of Iran

In this paper, three samples of green nano pigments based on chromium oxide containing Cr2O3, CoCr2O4 and Al2O3-Cr2O3 were synthesized in the aqueous solution by hydrothermal method and they were used for ceramic decoration . For sample preparation, appropriate amounts of precursors were dissolved in distilled water and pH of the solution was controlled by NaOH and Na2CO3. Then samples were put into an autoclave and it was heated at 180°C. The prepared precipitates were washed with distilled water and dried at 100oC. The prepared samples are in the powder shape and were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and UV/Visible absorption spectra. The results of XRD analysis show that Cr2O3 and CoCr2O4 were crystallized in a single-phase structure while Al2O3-Cr2O3 was crystallized in multi phase structure. SEM images show that the nano pigments were agglomerated while the mean particle size for all three compounds is about 80-100 nm. UV/Vis spectra of the dispersed samples in the water solution confirm a green color for the samples.