The effect of pH solution on the structure and antibacterial activity of zinc oxide nanostructure synthesized by sol-gel method

Zinc oxide (ZnO) nanostructure is one of the emerging materials because of its excellent properties. It offers various interesting applications from photocatalyst, optoelectronics, antibacterial agent, cosmetics and sensors. The synthesis of this material is being explored to optimize the structure in regards to its possible applications. One of the simple methods to prepare the ZnO nanostructure is sol-gel. Optimizing the synthesis parameters enables to produce the nanostructure material with different characteristics. The effect of pH solution during the fabrication process on the morphological of ZnO nanostructures and their antibacterial activity was studied. The synthesis was conducted using zinc acetate as a precursor at 60 ℃ for 5 h and two different pH, pH 7 and 9. The characterization was conducted by Fourier Transform Infrared (FTIR) spectroscopy and Scanning Electron Microscope (SEM) to check the formation of ZnO nanostructure, while UV-Vis spectroscopy was used to observe the antibacterial activity. The results show that ZnO nanostructures were formed at both two different pH solutions, pH 7 and 9, having wire-like and rod-like structures, respectively. Both nanostructures demonstrate their capability in inhibiting bacterial growth. The ZnO nanostructure synthesized at pH 7 had greater antibacterial activity than the ZnO synthesized at pH 9. These results confirm that pH solution during synthesis ZnO nanostructure affects the ZnO's structure and antibacterial activity.