J. Mater. Sci. Technol. ›› 2014, Vol. 30 ›› Issue (11): 1108-1117.DOI: 10.1016/j.jmst.2014.07.013

• Orginal Article • Previous Articles     Next Articles

Co-Doped ZnO Nanoparticles:Structural,Morphological,Optical,Magnetic and Antibacterial Studies

N.Mohamed Basith1,2,J.Judith Vijaya1,*,L.John Kennedy3,M.Bououdina4,5,S.Jenefar6,V.Kaviyarasan6   

  1. 1 Catalysis & Nanomaterials Research Laboratory,Department of Chemistry,Loyola College (Autonomous),Chennai 600034,India; 2 P.G.& Research Department of Chemistry,The New College (Autonomous),Chennai 600014,India; 3 Materials Division,School of Advanced Sciences,Vellore Institute of Technology (VIT) University,Chennai Campus,Chennai 600127,India; 4 Nanotechnology Centre,University of Bahrain,PO Box 32038,Bahrain; 5 Department of Physics,College of Science,University of Bahrain,PO Box 32038,Bahrain; 6 Centre for Advanced Studies in Botany,University of Madras,Chennai 600025,India
  • Online:2014-11-20 Published:2014-12-12
  • Contact: *Corresponding author.Prof,Ph.D.; Tel.:t91 44 28178333; Fax:t91 44 28175566; E-mail address: jjvijayaloyola@yahoo.co.in (J.J.Vijaya).

Abstract: Un-doped and Co-doped ZnO nanoparticles (NPs) with different weight ratios (0.5,1.0,1.5,and 2.0 wt% of Co) were synthesized by a facile and rapid microwave-assisted combustion method using urea as a fuel.The prepared NPs were characterized by X-ray diffraction (XRD),high resolution scanning electron microscopy (HR-SEM),energy dispersive X-ray analysis (EDX),diffuse reflectance spectroscopy (DRS),photoluminescence (PL) spectroscopy and vibrating sample magnetometry (VSM).XRD patterns refined by the Rietveld method indicated that Co-doped ZnO had a single pure phase with wurtzite structure suggesting that Co2+ ions would occupy Zn2+ ionic sites within the ZnO crystal lattice.Interestingly,the morphology was found to convert substantially from grains to nanoparticles with close-packed periodic array of hexagonal-like shape and then into randomly distributed spherical NPs with the variation of Co-content.The optical band gap estimated using DRS was found to be red-shifted from 3.22 eV for the un-doped ZnO NPs then decrease up to 2.88 eV with increasing Co-content.PL spectra showed a strong green emission band thus confirming the formation of pure single ZnO phase.Magnetic studies showed that Co-doped ZnO NPs exhibited room temperature ferromagnetism (RTFM) and that the saturation magnetization attained a maximum value of 2.203 × 10−3 emu/g for the highest Co-content.The antibacterial studies performed against a set of bacterial strains showed that the 2.0 wt% Co-doped ZnO NPs possessed a greater antibacterial effect.