Antibacterial activity of TiO₂ and TiO₂ composites nanopowders prepared by hydrothermal method

In this work, some inorganic metal oxides such as titanium dioxide (TiO₂), iron oxide (Fe₂O₃) and indium oxide (In₂O₃) nanopowders were prepared by a hydrothermal technique. The TiO₂ was mixed separately with Fe₂O_3, In₂O₃ and both mixtures were used to prepare three composite nanopowders (TiO₂–Fe₂O₃, TiO₂–In₂O_3, and TiO₂–Fe₂O₃–In₂O₃) at (1:1, 1:1 and 1:1:1) mole ratio respectively. The best conditions at 400 °C annealing temperatures were determined. The nanopowders were investigated and analyzed at different parameters; structure and surface morphology of powders were characterized by x-ray diffraction (XRD), scanning electron microscopy (SEM) techniques, atomic force microscopy (AFM), and fourier transform infrared spectroscopy (FTIR). The results of antibacterial activity for TiO₂ and its composites with two types of bacteria Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus Aureus), showed an increase in activity with increasing concentration of TiO₂ and annealing temperature. It was observed that the prepared composites were more effective in inhibiting different bacterial growth. (paper)