Zinc oxide (ZnO) is an attractive semiconductor material for photocatalytic applications,
owingtoits opto-electronic properties. Its performances are, however, strongly affected by the surface
and opto-electronic properties (i.e., surface composition, facets and defects), in turn related to the
synthesis conditions. The knowledge on howthese properties can be tuned and howtheyarereflected
on the photocatalytic performances (activity and stability) is thus essential to achieve an active and
stable material. In this work, we studied how the annealing temperature (400 C vs. 600 C) and the
addition of a promoter (titanium dioxide, TiO2) can affect the physico-chemical properties of ZnO
materials, in particular surface and opto-electronic ones, prepared through a wet-chemistry method.
Then, we explored the application of ZnO as a photocatalyst in CO2 photoreduction, an appealing
light-to-fuel conversion process, with the aim to understand how the above-mentioned properties
can affect the photocatalytic activity and selectivity. We eventually assessed the capability of ZnO to
act as both photocatalyst and CO2 adsorber, thus allowing the exploitation of diluted CO2 sources as
a carbon source.
