Semicrystalline SrTiO₃ -Decorated Anatase TiO₂ Nanopie as Heterostructure for Efficient Photocatalytic Hydrogen Evolution

The coupling of TiO₂ and SrTiO₃ through elaborate bandgap engineering can provide synergies for highly efficient photocatalysts. To further improve the separation between photogenerated electrons and holes, a nano-heterostructured combination of semicrystalline SrTiO₃ (S-SrTiO₃ ) and anatase TiO₂ nanoparticles is designed, and an optimized interface is achieved between uniformly grown S-SrTiO₃ and metal organic framework (MOF)-derived anatase TiO₂ through a controlled hydrothermal process. Besides tuning of the bandgap and broadening of the absorption spectral range, S-SrTiO₃ particles alleviate charge carrier recombination benefiting from the coupling of the semicrystalline SrTiO₃ around the interface. Additionally, highly dispersed S-SrTiO₃ on TiO₂ provides a good spatial distribution of active sites and the abundant carbon remained from MOF may reduce charge transport resistance. Moreover, the rapid transfer within the nano-heterostructure promotes the separation of the photogenerated charge carriers. With the above predominant architecture, when used as a photocatalyst, the as-synthesized S-SrTiO₃ /TiO₂ heterostructure exhibits exceptionally high photocatalytic performance of 13 005 µmol h^-1 g^-1 for H₂ production, exceeding most oxide-based photocatalysts reported. This study might provide mechanistic insights into a new perspective for the design and preparation of photocatalysts with novel structure and enhanced catalysis activity.