SPHEROIDAL ZINC OXIDE NANOPARTICLES SYNTHESIZED BY SEMICONTINUOUS PRECIPITATION METHOD AT LOW TEMPERATURES

The synthesis of spheroidal high purity zinc oxide (ZnO) and crystal size in a range of 20 and 45 nm, using the semicontinuous precipitation method is reported in this work. The ZnO nanoparticles (ZnO-NPs) were made by hydrolysis of Zn(NO3)2 with NaOH aqueous solution and precipitation at temperatures below 90 °C. The ultrafine powder of ZnO was analyzed by X-ray diffraction (XRD), where the formation of ZnO nanoparticles and hexagonal crystal structure (wurtzite) was corroborated. Spheroidal nanoparticles were observed by transmission electron microscopy (TEM) and energy dispersive aX-ray (EDX) spectra confirming the presence of high purity ZnO-NPs. A factorial experimental model 23 was performed to grant statistical validity of the experimental procedure. The antibacterial activity of ZnO-NPs was tested by the agar disk diffusion method, against S. aureus and E. coli.