Anchoring ultrafine metallic and oxidized Pt nanoclusters on yolk-shell TiO2 for unprecedentedly high photocatalytic hydrogen production

We demonstrate an alkali modification process to produce highly dispersed ultrafine Pt nanoclusters with metallic Pt-0 and oxidized Pt2+ species as co-catalyst anchored on nanosheet-constructed yolk-shell TiO2 (NYTiO2-Pt) acting as light harvesting reactor for highly efficient photocatalytic H-2 production. Benefiting from the high surface area, highly dispersed ultrafine Pt nanoclusters (similar to 0.6 nm) with Pt-0 and Pt2+ species and special nanosheet-constructed yolk-shell structure, this novel light harvesting reactor exhibits excellent performance for photocatalytic H-2 production. The NYTiO2-Pt-0.5 (0.188 wt% Pt) demonstrates an unprecedentedly high H-2 evolution rate of 20.88 mmol h(-1) g(-1) with excellent photocatalytic stability, which is 87 times than that of NYTiO2-Pt-3.0 (0.24 mmol h(-1) g(-1), 1.88 wt% Pt), and also much higher than those of other TiO2 nanostructures with the same Pt content. Such H-2 evolution rate is the highest reported for photocatalytic H-2 production with such a low Pt content under simulated solar light. Our strategy here suggests that via alkali modifying the photocatalysts, we can not only enhance the H-2 production for solar energy conversion but also significantly decrease the noble metal content for cost saving.