Nanoparticles have attracted great interest recently due to their unique physical and chemical properties, which are different from those of either the bulk materials or single atoms [6]. In recent years, many researchers have focused on cadmium oxide (CdO) due to their applications in several areas of research, specifically in optoelectronic and other applications, including solar cells, phototransistors, photodiodes, transparent electrodes and gas sensors [2]. Cadmium oxide (CdO) is n-type semiconductor used as a transparent conductive material prepared as a transparent conducting film back. Various methods have been used for the synthesis of CdO nanoparticles such as thermal process, precipitation method, sonochemical method and microemulsion, but these methods have limited control to achieve technological grade particles for their industrial applications and these procedure are not cost-effective and complex approach is involved which are not environmental friendly. Hence, green synthesis of CdO is so important approach for industrial application. In this work, CdO nanoparticles were prepared by simple and cheap strategy using
Calotropis procera plant. These green CdO bio-nanoparticles were characterized by TEM, SEM, XRD and DLS.