Light-driven processes for fuel production and cultural heritage remediation

Sunlight in an appealing energy source exploitable for a sustainable and equal development of human society, being abundant, widespread and cheap, on a scenario of adaptation strategies for facing the climate change happening on Earth surface. Several kind of chemical reactions required to sustain the society, from fuel production to environmental remediation, can be potentially run exploiting the light as energy source. A light-activated catalyst (photocatalyst) is often needed to allow such reactions to occurs, able to both absorb the photons and decrease the kinetic barrier. The aim of this work was to prepare some earth-abundant oxide-based semiconductor (SC) materials and assessed them in some photocatalyzed reactions, using a selected SC for each process. Titanium dioxide (TiO2) was used for H2 production from biomass, zinc oxide (ZnO) and a mixed iron-copper oxide (CuFeO2) in CO2 photoreduction, while a calcium-based plaster (marmorino) modified with TiO2 and ZnO, was used in cultural heritage photoremediation (self-cleaning). Different characterization techniques were exploited to achieve a comprehensive knowledge of structural, morphological, optical and surface properties of the prepared materials. Finally, the physical-chemical properties of these oxides were correlated to the photoactivity, aiming to understand how these features affect, negatively or positively, the performances of a given reaction.