Co-doped ZnO nanoparticles synthesized by an adapted sol–gel method: effects on the structural, optical, photocatalytic and antibacterial properties


Pure and Co-doped ZnO nanoparticles were synthesized with different cobalt levels (1–10 mol%) via adapted sol–gel method using water as solvent and characterized by X-ray diffraction, transmission electron microscopy, Raman spectroscopy and photoacoustic absorption spectroscopy. The results showed that all the samples have hexagonal wurtzite structure, with no evidence of any secondary phases until 10 mol% of the dopant. The average crystallite size of the samples was in the range of 25–50 nm, do not showing significant differences with the increase of the dopant level. However, the band gap energy of the nanoparticles decreases from 2.98 eV (pure ZnO) to 1.95 eV (10 mol% of Co). The photocatalytic activity of the samples was evaluated on the removal of methylene blue under visible light irradiation, which revealed an efficiency reduction by Co-doping ZnO. The antibacterial property was carried out indicating activity of the prepared samples against gram-positive bacteria.

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The authors are grateful to GEFF for the PAS analysis, DFI and COMCAP/UEM for the other equipment used in this work, and to Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq), Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) and Fundação Araucária for financial support.

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Correspondence to Michele Karoline Lima.

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Lima, M.K., Fernandes, D.M., Silva, M.F. et al. Co-doped ZnO nanoparticles synthesized by an adapted sol–gel method: effects on the structural, optical, photocatalytic and antibacterial properties. J Sol-Gel Sci Technol 72, 301–309 (2014).

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  • Co-doped ZnO
  • Band gap energy
  • Visible light irradiation
  • Photocatalysis
  • Antimicrobial