Perovskite oxide nanosheets with tunable band-edge potentials and high photocatalytic hydrogen-evolution activity.

Perovskite nanosheets of HCa(2-x)Sr(x)Nb3O10 and HCa2Nb(3-y)Ta(y)O10 with controlled band-edge potentials were prepared. They worked as highly efficient heterogeneous photocatalysts for H2 evolution from a water/methanol mixture under band-gap irradiation. The activity was found to depend on the composition. The highest activity was obtained with HCa2Nb2TaO10 nanosheets, recording an apparent quantum yield of approximately 80% at 300 nm, which is the highest value for a nanosheet-based photocatalyst reported to date.