H NMR Study of the HCaNbO Photocatalyst with Different Hydration Levels.

The photocatalytic activity of layered perovskite-like oxides in water splitting reaction is dependent on the hydration level and species located in the interlayer slab: simple or complex cations as well as hydrogen-bonded or non-hydrogen-bonded HO. To study proton localization and dynamics in the HCaNbO·HO photocatalyst with different hydration levels (hydrated-α-form, dehydrated--form, and intermediate-β-form), complementary Nuclear Magnetic Resonance (NMR) techniques were applied. H Magic Angle Spinning NMR evidences the presence of different proton containing species in the interlayer slab depending on the hydration level.