Formation of hexagonal plate shaped ZnO microparticles – A study on antibacterial and magnetic properties

Abstract The focus of this work is to realize ZnO microparticles with simultaneously enhanced antibacterial and magnetic properties through a double cationic (Mg+Co) doping. Undoped and magnesium (Mg)+ cobalt (Co) doped ZnO microparticles were synthesized using a cost-effective simple soft chemical route. Their surface morphological, magnetic, antibacterial and structural properties were investigated. Antibacterial studies of the prepared samples were carried out against a Gram Positive and Gram Negative bacteria. From the antibacterial studies, it is found that the double cationic doped ZnO microparticles exhibit superior antibacterial efficiency compared with undoped and single cationic doped ZnO microparticles. The FESEM images show that the undoped and single cationic (Mg/Co) doped ZnO particles have hexagonal block structures of micro scale dimensions whereas the double cationic doping causes the formation of hexagonal plate structures having near nanoscale thickness (~150 nm), thereby increasing the effective reactive surface area. The magnetization curves show that the coexistence of Mg 2+ and Co 2+ ions in the ZnO lattice causes a pronounced increase in the ferromagnetic behavior, already present in the undoped and single cationic doped ZnO material. The XRD, FTIR and PL results support the discussion on the antibacterial and magnetic results. The EDAX profiles and the compositional mapping images confirm the presence of expected proportions of the constituent elements and their uniform distribution in the final product. Structural studies show that the products exhibit hexagonal wurtzite structure of ZnO without any secondary phases.