Photocatalytic inactivation of E. coli using nano-size bismuth oxyiodide photocatalysts under visible light

Bismuth oxyiodide photocatalyst has been prepared via solvothermal method at 443 K with reaction time 13 h using ethylene glycol (BiOI-EG) and hydrothermal method at 353 K with reaction time 5 h using distilled water (BiOI-DW). The effect of difference in the solvent, temperature and reaction time plays a key role to the evolution on the morphologies and performances of BiOI samples. The materials obtained were characterized by different techniques. Although both prepared catalysts were of high purity and have the same calculated band gap energy (1.9 eV) but BiOI synthesized with a Teflon-lined stainless-steel autoclave using ethylene glycol exhibits excellent antimicrobial activity under visible-light than BiOI synthesized by water bath using distilled water. This can be attributed to high surface area of BiOI-EG (410 m2/g) compared with that of BiOI-DW (296.6 m2/g) and different in the morphology of both prepared photocatalyst. Also, the experimental results showed that the photocatalytic inactivation efficiency of Escherichia coli strain (105 CFU/mL) using 0.75 g/L BiOI-EG was almost totally removed within 45 min irradiation, and significantly higher than that of BiOI-DW under visible light.