Synthesis and growth mechanism of CdO nanoparticles prepared from thermal decomposition of CdSO₃ nanorods

Abstract

In the present study, the transformation of acidic solution of cadmium acetate and sodium dithionite into CdSO₃ nanorods through microemulsion/hydrothermal reaction is reported. The reaction time and microemulsion media are two factors that subjected to investigation. The reaction time was found to be crucial for the formation of nanorods but the microemulsion media have no important effect on the morphology of the products. The CdSO₃ nanorods were yellow crystalline product having diameter of 70 nm as observed from scanning electron microscopy (SEM) results. The X-ray diffraction (XRD) pattern clearly shows the formation of CdSO₃. The CdO nanoparticles (43 nm) were obtained by thermal decomposition of CdSO₃ product at 700 °C. Powder XRD and SEM microscopy were used to characterize the obtained nanoparticles. The XRD analysis confirmed the purity of the as-prepared CdO. The reasonable growth mechanism for the formation of CdSO₃ and CdO were also proposed. The direct band gap of the CdO nanoparticles showed blue shift of 1.0 eV, comparing with that of the bulk CdO.