Influence of Li-Co co-doping on structural and optical properties as well as on antibacterial activity of ZnO

We report the influence of the codoping of Li and Co into ZnO on the structural and optical properties as well as on the antibacterial activity of ZnO nanostructures, synthesized via co-precipitation technique. Confirmed by x-ray diffraction (XRD), the prepared samples (ZnO, Li0.015Co0.015Zn0.97O and Li0.03Co0.03Zn0.94O) exhibit hexagonal wurtzite structures where inclusion of the dopants (Li and Co) into the ZnO reduces the crystallite size from 16.43 +/- 1.02 to 15.12 +/- 1.02 nm. Scanning electron microscopy (SEM) reveals the shape of the particles to be spherical while energy-dispersive spectroscopy (EDS) confirms the elemental composition of the samples. The doping of Li and Co reduces the oxygen content in the ZnO, significantly for Li0.015Co0.015Zn0.97O. Ultraviolet-visible (UV-vis) spectroscopy and photoluminescence (PL) determine a similar, approximately, band gap of the nanostructures. The emission intensity is found to be maximum for Li0.015Co0.015Zn0.97O in the visible range and increased antibacterial activity is evidenced for Li0.03Co0.03Zn0.94O against pseudomonas aeruginosa bacterium.