Synthesis and coloring properties of Cd(S1-xSex) pigments by precipitate-hydrothermal method

Cd(S1−x Se x ) pigments (red to yellow) were synthesized by precipitate-hydrothermal method. The structure, morphology and hue of the powder were characterized by X-ray diffractometry (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDAX) and CIE chromaticity. The optimum synthesis conditions were obtained and reaction mechanism was further analyzed as well. The results show that molar ratio of S to Se, pH value and hydrothermal reaction conditions have great effects on the hues of the pigments. Pigments with vivid hues are obtained under the conditions that pH value is about 13.0, hydrothermal reaction condition is at 140 °C for 4 h or at 160 °C for 6 h. The reaction mechanism is that Se2− of Cd(S1−x Se x ) substitutes S2− of CdS and then forms a continuous solid solution.