Room Temperature Green Synthesis of CdO Nanoparticles Using Aqueous Extracts of Callistemon Viminalis

Room Temperature Green Synthesis of CdO Nanoparticles Using Aqueous Extracts of Callistemon Viminalis

Sustainable, environmentally clean synthesis/production of metals, metal oxide nanoparticles and a host of other strategically important organic and inorganic compounds/materials of interest is of great necessity as the adverse effects of environmental pollution brought about using traditional/existing methods of synthesis can be felt along our ecosystems. The need for environmentally safer yet costeffective methods of synthesis are therefore of real necessity and are the subject of increasing interest within the scientific community. Green syntheses of such compounds of interest using plant extracts offer an environmentally safer way of producing these desired materials/compounds. In this contribution the green synthesis of CdO nanoparticles at room temperature using aqueous extracts from red flowers of the plant Callistemon viminalis is reported for the first time. X-ray diffraction analysis measurements carried out after calcining the samples at 500°C in air confirmed the formation of crystalline CdO while Scanning Electron Microscopy showed that CdO crystallized as nanospheres. X-Ray Fluorescence spectroscopy, X-ray photoelectron results were used to confirm the presence of Cd2+ and O2- states as well as the presence of Cd-O bonds that point to the formation of CdO nanopowders of high purity. Room temperature photoluminescence spectroscopy with an excitation source of 325 nm suggest a broad size distribution of the nanoparticles, the presence of many surface-defects in the nanosized CdO and the estimated band gaps to be 2.88 and 2.57 eV. This synthesis which does not require the use of organic solvents and surfactants is a rapid, easy and environmentally friendly way of producing multifunctional CdO nanopowders.