Molecules, Vol. 28, Pages 4798: Effect of the Synthetic Parameters over ZnO in the CO2 Photoreduction

Molecules, Vol. 28, Pages 4798: Effect of the Synthetic Parameters over ZnO in the CO2 Photoreduction

Molecules doi: 10.3390/molecules28124798

Authors: Danny Zanardo Giulia Forghieri Elena Ghedini Federica Menegazzo Alessia Giordana Giuseppina Cerrato Elti Cattaruzza Alessandro Di Michele Giuseppe Cruciani Michela Signoretto

Zinc oxide (ZnO) is an attractive semiconductor material for photocatalytic applications, owing to its 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 how these properties can be tuned and how they are reflected 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.