Pt-surface oxygen vacancies coupling accelerated photo-charge extraction and activated hydrogen evolution

Semiconductors-based heterogeneous photocatalytic water splitting has been extensively studied, but it still remains challenging to accelerate the separation of electron–hole pairs and facilitate the reaction kinetics. Here we report a general strategy to fabricate highly efficient Pt/TiO₂ photocatalyst by coupling the Pt co-catalysts and surface oxygen vacancies (V_O) of TiO₂. TiO₂ was pre-modified with alkali or alkaline earth metals ion solutions, which produce a large number of surface hydroxyl on TiO₂. Subsequently, the photodeposited Pt sub-nanoparticles substitute surface hydroxyl and induce surface V_O on TiO₂. The coupling of Pt and surface V_O on TiO₂ can accelerate the extraction of photo-charges through the interaction of Pt–V_O–Ti bonds and reduce the hydrogen evolution barrier, thereby promoting the photocatalytic activity. The synthesized Pt-V_O-TiO₂ sample exhibits a photocatalytic hydrogen evolution activity as high as 1.5 L·g⁻¹·h⁻¹, which is 2.2 times that of traditional Pt/TiO₂. Our findings in-depth understand the synergistic effect of co-catalysts and defects on photocatalysis and open up new possibilities for achieving robust photocatalytic water splitting.