氧化锌(ZnO)是光催化应用的有吸引力的半导体材料,由于其光电特性。它的表现是,然而,受表面和光电特性的强烈影响(即,表面成分,刻面和缺陷),又与合成条件有关。因此,关于如何调节这些性能以及如何将其反映在光催化性能(活性和稳定性)上的知识对于获得活性和稳定的材料至关重要。在这项工作中,我们研究了退火温度(400°Cvs.600°C)和添加促进剂(二氧化钛,TiO2)可以影响ZnO材料的物理化学性质,特别是表面和光电的,通过湿化学方法制备。然后,我们探索了ZnO作为光催化剂在CO2光还原中的应用,一个吸引人的光-燃料转换过程,目的是了解上述性质如何影响光催化活性和选择性。我们最终评估了ZnO作为光催化剂和CO2吸附剂的能力,从而允许开发稀释的CO2源作为碳源。
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.