Synthesis and characterization of environmentally benign calcium-doped Pr2Mo2O9 pigments: Applications in coloring of plastics

A new class of environmentally benign rare earth pigments of general formula Pr2−xCaxMo2O9−δ (x ranges from 0 to 1.0) displaying colors ranging from green to yellow were synthesized by traditional solid-state route, as alternatives to lead, cadmium and chromium colorants. The products were characterized by X-ray powder diffraction, UV–vis spectroscopy and CIE-L*a*b* 1976 color scales. The coloring mechanism is based on the strong absorptions of the pigments in the blue and red regions due to electronic transitions between 4f2→4f15d1 states of Pr3+. The designed pigments consist of non-toxic elements and further found to be thermally and chemically stable. The yellow–green pigments were found to be interesting alternatives to existing toxic pigments for coloration of plastics.

Graphical abstractA new class of environmentally benign rare earth pigments of general formula Pr2−xCaxMo2O9−δ (x ranges from 0 to 1.0) displaying colors ranging from green to yellow were synthesized by traditional solid-state route, as alternatives to lead, cadmium and chromium colorants. The yellow–green pigments were found to be interesting alternatives to existing toxic pigments for coloration of plastics.Figure optionsDownload full-size imageDownload as PowerPoint slide