Photocatalytic Bacterial Inactivation Using Bi-doped TiO2/Kaolinite Under Visible Light Irradiation

Abstract

Bismuth-doped TiO2 immobilized on kaolinite (Bi-TiO2-K) were prepared via sol-gel method, then calcined at 450oC using kaolinite as the matrix and Bi (NO3)3 as the Bi3+ cationic source. The obtained Bi-TiO2-K photocatalyst were characterized using X-ray diffraction (XRD), infrared absorption spectroscopy, diffuse reflectance spectroscopy, energy-dispersive X-ray spectroscopy (EDX) and scanning electron microscopy (SEM). The photocatalytic activity of the Bi-TiO2-K was investigated on the bacterial inactivation of Escherichia coli (EC) and Staphyloccus aureus (SA) in water solution under visible light irradiation. The photocatalytic activity test for inactivating EC and SA bacteria was determined at room temperature and pH 7. Under visible light irradiation for 180 min, the Bi-TiO2-K photocatalyst have higher bacterial inactivation as compared to unmodified Bi-TiO2 photocatalyst. After 180 min irradiation time was required to achieve bacterial reduction for an average bacterial inoculum size of 9.5 × 106 CFU mL−1. Finally, Bi doped TiO2-K could be an efficient photocatalyst for bacterial strain inactivation.