The cadmium-loaded CaCO3/PMMA nanocomposites were prepared from a natural carbonate source (dolomite, CaMg(CO3)(2)) using biomimetic method. The XRD results showed that the synthesized product has exhibited a crystalline and rhombohedral structure with a size range of 30-40 nm. The absorption and emission values of CPCD6 (CaCO3/PMMA: Cd (0.12 M)) nanoparticles are red-shifted, and the band gap values depict blue-shifted (2.8 eV). The HR-TEM analysis of the sample indicates that the products have aggregated with spherical-like structures. The TG-DTA analysis revealed good thermal stability approximately at 830 degrees C. The photocatalytic analysis was performed on the CPCD6 nanocomposite to remove methylene blue (MB) and methyl orange (MO) dyes from an aqueous solution under UV-visible light. The results show that the photocatalyst (CPCD6) exhibits high degradation efficiency for methylene blue (MB) (93%) when compared with methyl orange (MO) (89%) dyes. To evaluate the effectiveness of the product, several scavengers (AA, AgNO3, EDTA 2Na, and IPA) are employed. The CPCD6 nanocomposites showed great potential for the removal of organic dyes from aqueous media.