The hydrothermal processing of iron oxides from bacterial biofilm waste as new nanomaterials for broad applications.

Iron oxides and their hydroxides have been studied and analysed with properties of their mutual transformations under different hydrothermal conditions being indicated. Amorphous bacteria nanowires produced from biofilm waste were investigated under the influence of pH at a fixed duration (20 h) and reaction temperature (200 °C). The morphology, structure, and particle size of the transformation of hematite (α-FeO) was obtained and characterised with SEM, XRD, FTIR, and particle sizer. The optimal conditions for the complete conversion of amorphous iron oxide nanowires to crystalline α-FeO is under acidic conditions where the pH is 1. The flower-like α-FeO structures have photocatalytic activity and adsorbent properties for heavy metal ions. This one-pot synthesis approach to produce α-FeO at a low cost would be greatly applicable to the recycling process of biofilm waste in order to benefit the environment.