Solar photocatalytic inactivation of Fusarium Solani over TiO2 nanomaterials with controlled morphology—Formic acid effect

Photocatalysis is a well known efficient process for the decontamination of wastewaters pollutants. In the last decade an intense research was focused on the elaboration of well tuned TiO2 photocatalysts with the basic idea to understand the relationship between exposed facet and reactivity. In this work, four TiO2 morphologies are examined namely: nanotubes (NT), nanoplates (NPL), nanorods (NR) and nanospheres (NS). The solar photocatalytic properties are compared in the disinfection of a Fusarium solani inoculated solution. Disinfection using the solar light has been studied and the effect of formic acid (FA) was examined. We demonstrated, for the first time, that the solar inactivation of the resistant spores of Fusarium in water is related to the exposed TiO2 facets. At very low concentration of photocatalyst, the inactivation of F. solani over TiO2 nanospheres shows the best disinfection efficiency with respect to the others morphologies. Experiments on simultaneous photocatalytic decontamination of FA and inactivation of F. solani showed that the presence of FA strongly retards the disinfection reaction in the case of TiO2 nanospheres while the FA degradation occurred simultaneously with F. solani inactivation in the case of TiO2 NT. This result shows the interest of TiO2 NT for the decontamination and disinfection of wastewaters containing acidic pollutants and pathogens.