Development of Hybrid Titanium Oxide-based Systems for the Surface Stabilization of Reactive Oxygen Radicals

Abstract

Hybrid materials based on amorphous titanium or zirconium oxide with specific organic ligands show oxidative activity toward organic pollutants in the dark, owing to the generation and unusual long-term adsorption of superoxide radical anions on their surfaces. Here an overview of perspectives for the development of these materials and their processing towards technological applications is presented, focusing on the TiO2-acetylacetonate system. First, the tuning and optimization of the sol-gel synthesis conditions is discussed, aimed at yielding the desired products, such as chemical gels or stable sols. Then the thermal stability of the hybrid dried gels is assessed, in relation to their ability to form superoxide radicals. Finally, electrospinning is introduced as an efficient and ecofriendly technique to support the xerogel powders embedding them in a porous nanofiber polymer network. The preliminary characterization of the electrospun composite polyvinylpyrrolidone-hybrid TiO2 reveals potentialities for the realization of air filters or antimicrobial gauzes.