The antibacterial property of ZnO nanopowder with different concentration of sodium hydroxide prepared by hydrothermal method

Abstract Zinc oxide Nanopowder was synthesized through a hydrothermal method in this study. The effect of three different NaOH concentrations on the properties of ZnO Nanopowder was studied. The hexagonal wurtzite structure of all ZnO Nanopowder is confirmed by X-ray diffraction analysis, with average crystallite sizes in the range of (33.5–30.4) nm. It can be observed that the crystallite size become smaller with increasing NaOH concentration. Scanning electron microscopy analysis indicates that ZnO has hexagonal shape uniform particle size distribution and their morphology was grain-like. Atomic force microscope shows that the ZnO Nanopowder average surface roughness decreased from (9.33–5.06) nm due to increasing NaOH concentration. The Fourier transform infrared spectroscopy peaks indicate successful preparation of ZnO Nanopowder. From the optical absorption spectra the band gap energy has been calculated. The NaOH concentrations have been found very effective on the energy gap value. So, its increased from (3.27 to 3.36) eV when the NaOH concentration is increased. ZnO Nanopowder shows high antibacterial activity against P.aeuruginosa and S. aureus bacteria. The ZnO Nanopowder shows has very high antibacterial activity on gram-positive (S. aureus) compared with antibacterial activity on the gram-negative (P.aeuruginosa) bacteria.