Synthesis and characterisation of Fe3O4/MWCNT/ZnO nanocomposites covered by a soft template as a new antibacterial agent

Abstract

This study successfully developed a new antibacterial agent based on Fe3O4/MWCNT/ZnO nanocomposites prepared using diethylamine as a soft template. The prepared samples were characterised using x-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, energy-dispersive x-ray spectroscopy, vibrating sample magnetometry, ultraviolet-visible spectroscopy, and antibacterial tests by the diffusion method. The results of the data analysis showed that Fe3O4/MWCNT/ZnO nanocomposites were composed of Fe3O4, MWCNT, ZnO with inverse cubic spinel, hexagonal, and hexagonal wurtzite structures, respectively. The nanocomposite particles tended to agglomerate and their size decreased with increasing volume of added diethylamine in the range of ∼23-26 nm. The nanocomposites remain stable even after being stored for more than 3 years. The nanocomposites had superparamagnetic properties with saturation magnetisation values of 24 to 31 emu g−1 and band gap values of 2.96 to 2.99 eV. The diameters of the bacterial inhibition zone of the nanocomposites were 12.57-20.38 mm, 14.25-17.25 mm, and 14.63-16.38 mm against E. coli, S. aureus, and B. subtilis, respectively. Therefore, the combination of Fe3O4, MWCNT, ZnO, and diethylamine with natural base materials such as iron sand has good potential to develop new antibacterial agents.