Photocatalytic Inactivation of Bacteria in the Presence of Tungsten-Modified Titania under Visible Light Irradiation

Photocatalytically active materials based on titania modified with tungsten (5-30 wt %) have been synthesized. Specific features of the formation of these materials and their physicochemical and photocatalytic properties have been described. It has been found that the modification of titania with tungsten provides the formation of nanodispersed powders (7.2-96.7 nm) with a free specific surface area of 6.4-215 m(2)/g. Using the example of gram-negative bacteria Pseudomonas fluorescens, it has been shown that photocatalysts based on titania modified with tungsten (10-30 wt %) and calcined at 600 degrees C are highly efficient for the photocatalytic inactivation of the microbiota. The highest photocatalytic antibacterial activity has been exhibited by the 600-W-20 sample. Most of the bacteria are inactivated under irradiation with visible light of natural origin at an illuminance (E) of 14 500 lx during the first 20-45 min. Upon the introduction of unmodified titania, the 600-W-5 sample, and a commercial P-25 photocatalyst from Degussa as a photocatalyst, no inhibition of bacterial growth has been detected.

Automated summary

Photocatalysts based on tungsten-modified titania have been synthesized and their formation, physicochemical properties, and photocatalytic performance have been investigated. The results show that tungsten modification enables the formation of nanodispersed powders with a large surface area. The modified titania exhibits highly efficient photocatalytic inactivation of gram-negative bacteria.