The influence of calcination temperature on structural and antimicrobial characteristics of zinc oxide nanoparticles synthesized by Sol–Gel method

The influence of different calcination temperatures on the molecular structure, optical, morphological and antimicrobial activity were investigated for Zinc Oxide nanoparticles (ZnO NPs) synthesized using green sol-gel method. The prepared ZnO NPs are calcined at 70 °C, 300 °C, 400 °C and 800 °C. The effect of different calcinations temperature on the characterization of the prepared samples were studied using X-ray Diffraction (XRD), High Resolution Transmission Electron Microscope (HRTEM), High Resolution Scanning Electron Microscope (HRSEM), Fourier Transform Infrared (FT-IR), and Ultraviolet–Visible Spectroscopy (UV–Vis). In addition, the potential antimicrobial activity of ZnO NPs were investigated against four different pathogenic bacterial strains: two strain of gram negative bacteria (Pseudomonas Aeruginosa and Klebsiella Pneumonia) and two strain of gram positive bacteria (Bacillus subtilis and Staphylococcus Aureus). The results showed that XRD, UV–Visible and FT-IR confirmed the presence of ZnO nanoparticles. HRTEM and HRSEM reveal that as the temperature increase the size of prepared sample increased and the agglomeration increases. The best size of rod shape ZnO NPs found at 300 and 400 °C. Zinc oxide NPs prepared at 300 °C calcination temperature have the superior antibacterial effect on the gram positive and gram-negative pathogenic bacteria.