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

Abstract

We demonstrate an alkali modification process to produce highly dispersed ultrafine Pt nanoclusters with metallic Pt0 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 H2 production. Benefiting from the high surface area, highly dispersed ultrafine Pt nanoclusters (~0.6nm) with Pt0 and Pt2+ species and special nanosheet-constructed yolk-shell structure, this novel light harvesting reactor exhibits excellent performance for photocatalytic H2 production. The NYTiO2-Pt-0.5 (0.188wt% Pt) demonstrates an unprecedentedly high H2 evolution rate of 20.88mmolh−1g−1 with excellent photocatalytic stability, which is 87 times than that of NYTiO2-Pt-3.0 (0.24mmolh−1g−1, 1.88wt% Pt), and also much higher than those of other TiO2 nanostructures with the same Pt content. Such H2 evolution rate is the highest reported for photocatalytic H2 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 H2 production for solar energy conversion but also significantly decrease the noble metal content for cost saving.