Photocatalytic overall water splitting on Pt nanocluster-intercalated, restacked KCa2Nb3O10 nanosheets: the promotional effect of co-existing ions†
Abstract
Promotional effects of co-existing ions on overall water splitting into H2 and O2 have been studied in bulk-type semiconductor photocatalysts (e.g., TiO2), but such an effect remains unexplored in two-dimensional nanosheet photocatalysts. Here we examined the effect of co-existing ions on the photocatalytic water splitting activity of Pt nanocluster-intercalated KCa2Nb3O10 nanosheets. Interestingly, not only anions, as usually observed in bulk-type photocatalysts, but also cations had a significant influence on the photocatalytic performance. The rates of H2 and O2 evolution over Pt/KCa2Nb3O10 as well as the product stoichiometry were improved in the presence of NaI. Iā ions were found to effectively suppress undesirable backward reactions, consistent with the previous work by Abe et al. (Chem. Phys. Lett., 2003, 371, 360ā364). On the other hand, Na+ ions in the reaction solution were exchanged for K+ in the interlayer space of KCa2Nb3O10 during the water splitting reaction, which promoted interlayer hydration and consequently improved photocatalytic performance.
- This article is part of the themed collection: Photocatalysis and Photoelectrochemistry