Co-Precipitation Synthesis of Tunable Cd _{1− <i>x</i>} Zn _<i>x</i> S Nanoparticles: Effect of Zinc Substitution on Structure and Optical Properties

Cd 1− x Zn x S nanoparticles with tunable optical and structural properties were successfully synthesized using a simple and cost-effective co-precipitation method. Influence of Zinc incorporation on the crystal phase, morphology, and also optical characteristics was systematically examined for compositions (ranging from x = 0.2, 0.4, 0.6, 0.8 and 1.0). Structural analysis by X-ray diffraction (XRD) and Raman spectroscopy results confirmed the formation of Cd 1− x Zn x S nanoparticles, with diffraction peaks gradually shifting toward higher angles as the Zn content increased, indicating successful substitution of Cd 2+ by Zn 2+ and contraction of the lattice. UV–Vis absorption measurements revealed a pronounced blue shift in the absorption edge with increasing Zn concentration, corresponding to a systematic widening of the optical band gap from CdS toward ZnS. Electron microscopy confirmed the formation of nanosized particles and compositional uniformity. The study demonstrates that the co-precipitation method provides an efficient route for producing compositionally tunable Cd 1− x Zn x S nanoparticles with controlled structural and optical properties. These findings highlight the suitability of Cd 1− x Zn x S nanomaterials for potential use in optoelectronic, photocatalytic, and energy-conversion applications.