Photocatalytic performance of titanium dioxide thin films from polymer-encapsulated titania

The performance of a proprietary catalyst (VN-TiO₂) was compared with standard P25 TiO₂ for removal of methylene blue in water using immobilized photocatalysis. Using a fiberglass disk as the support medium dip coated in the VN-TiO₂ solution and calcining, porous films with a high surface area (up to 109 m²/g) were produced without any modification. Although films formed with VN-TiO₂ on fiberglass disks had a reaction rate 50% lower than that of P25, the disks coated with VN-TiO₂ were mechanically robust in the reactor, compared to those coated with P25. The addition of only 15 wt % P25 in the VN-TiO₂ solution increased the reaction rate by 40%, while maintaining the mechanical stability. The reuse potential of both catalysts was tested, and the rates of deactivation were comparable for both catalysts. Deactivation occurred due to sustained adsorption of Methylene Blue intermediates, as well as a loss of active sites, because of heat treatment for reactivation. Low-priced fiberglass in combination with the easily impregnable polymer-encapsulated titania is a viable option for producing mechanically robust and uniform catalyst coating for immobilized photoreactors.