Hollow SrTiO3 photocatalyst with spatially separated OER and HER cocatalysts for photocatalytic overall water splitting

Spatially segregated the hydrogen and oxygen evolution sites are deposited on the outer and inner surfaces of hollow SrTiO3 spheres, respectively, for OWS. The spatially distributed Pt/SrTiO3/CoOx catalysts exhibited exceptional separation of photogenerated charges, resulting in 3-times higher stoichiometric OWS compared to Pt/SrTiO3 by enhancing interfacial spatial charge separation. [Display omitted] •Deposited H2/O2 evolution sites on the outer/inner surfaces of hollow SrTiO3 spheres.•Spatially separated of electron and hole pairs.•Exhibited hindered charge recombination and enhanced charge separation.•Showed 3 times higher stoichiometric OWS activity compared to Pt/SrTiO3. Overcoming the challenge of sluggish charge separation and the concurrent occurrence of overall water splitting (OWS) half reactions at the same catalytic sites is crucial for achieving efficient photocatalysis. This issue often leads to a high recombination rate and the back reaction of OWS. In this study, we addressed this challenge by enhancing interfacial spatial charge separation. Specifically, we designed hollow SrTiO3 spheres and spatially segregated the hydrogen and oxygen evolution sites on the outer and inner surfaces, respectively, for OWS. The spatially distributed Pt/SrTiO3/CoOx catalysts exhibited exceptional separation of photogenerated charges, resulting in 3-times higher stoichiometric OWS compared to Pt/SrTiO3. This work underscores the effectiveness of a well-tailored spatially distributed structure in promoting charge separation in photocatalysis, thereby opening avenues for the development of efficient artificial photosynthesis systems.