Grätzel-Type TiO2 Anatase Layers as Host for Pt Single Atoms: Highly Efficient and Stable Photocatalytic Hydrogen Production

Single atoms (SAs) represent not only a new frontier in classic heterogeneous catalysis but are also increasingly investigated as co-catalysts in photocatalytic reactions. In contrast to classic catalysis, many photocatalytic platforms require only a very low SA loading density to reach a saturated photocatalytic activity. As a result, an optimized light harvesting/carrier transport combination in the supporting semiconductor becomes the key aspect for the overall photocatalytic efficiency. In this work, it is demonstrated that Gratzel type mesoporous TiO2 layers represent an ideal host for Pt single-atoms (SAs) that allow for a highly effective photocatalytic H-2 generation. Using a layer with an optimized geometry, structure, as well as Pt SA loading, a photocatalytic H-2 production is achieved of up to approximate to 2900 mu L h(-1) (under irradiation at lambda = 365 nm and I = 65 mW cm(-2)) - a performance that is far superior to previous Pt SA/TiO2 structures based on TiO2 nanotubes, nanosheets, or metal organic frameworks. Moreover, such SA/substrate combination provides a highly stable H-2 production over time. The present work thus introduces the use of this classic TiO(2 )nanostructure as the most effective host for Pt SAs and its use for highly efficient photocatalytic H-2 production from aqueous solutions.

Automated summary

Single atoms are gaining attention in classic heterogeneous catalysis and photocatalytic reactions. The key to efficient photocatalysis lies in optimizing the light harvesting and carrier transport in the supporting semiconductor. This study demonstrates that Gratzel type mesoporous TiO2 layers are excellent hosts for Pt single atoms, enabling highly effective photocatalytic H-2 generation.