Enhanced photoluminescence, structural, morphological and antimicrobial efficacy of Co-doped ZnO nanoparticles prepared by Co-precipitation method
A. T. Ravichandran, R. Karthick
Abstract
ZnO nanoparticles have been successfully prepared by the co-precipitation process with Co: ZnO atomic ratio of 0–7%. The structural, morphological, optical and antibacterial properties of synthesized nanoparticles were investigated. X-ray diffraction (XRD) patterns, Field Emission Scanning Electron Microscopy (FESEM) images, Energy Dispersive X-ray Spectroscopy (EDX) analyses verify the nanopowders. Emission of ZnO enhances several times when Co2+ ion is added with crystals. The intensity much faster increases of the violet and blue emission bands than that of red and NIR emission bands. The XRD patterns showed the (100), (002) and (101) planes are indicated the formation of the single phase appear in the lattice. The crystallite size decrease from 42 nm to 34 nm for the nanoparticles as dopant concentration is increased. Morphological observations illustrate the development of nanoparticles with notable morphologies. The elemental composition of Co, Zn and O were observed from EDX analysis, which confirmed the purity of the as-prepared nanoparticles. PL spectra showed a strong ultraviolet and visible emission band which may be attributed to the cobalt doping leads to increase in oxygen vacancy and defects. Antibacterial activity of Co/ZnO nanoparticles against Staphylococcus aureus was found significantly higher than that of Escherichia coli microorganism.