Room Temperature Surfactant-Free Synthesis of Cobalt-Doped CaMoO4 Nanoparticles: Structural and Microstructural Insights

This study reports the successful synthesis of pure cobalt-substituted calcium molybdate powders (Co-doped CaMoO4) through a co-precipitation method conducted at room temperature, without the use of surfactants or hazardous organic solvents. The formation of solid solutions with x values ranging from 0.00 to 0.08 was confirmed by X-ray diffraction, Rietveld refinement, and Raman spectroscopy analyses. Elemental analysis using energy-dispersive X-ray spectroscopy showed a strong correlation between the experimental and nominal stoichiometries. The synthesized molybdate powders consist of micrometer-sized particles exhibiting diverse morphologies, including microspheres, flower-like architectures, and dumbbell-shaped particles. These agglomerates are composed of primary particles smaller than 43 nm. The specific surface area increased from 3.59 m2/g for the undoped CaMoO4 to 10.74 m2/g for the 6% Co-doped CaMoO4. These nanostructured powders represent promising host materials for 4f ions, making them potential candidates for solid-state lighting applications.