Spatial engineering of photo-active sites on g-C₃N₄ for efficient solar hydrogen generation

ZnFe₂O₄ modified g-C₃N₄ was successfully synthesized by a simple one-pot method. The visible-light-driven photocatalytic hydrogen production activity of g-C₃N₄ was significantly enhanced due to spatial engineering of the photo-active sites via ZnFe₂O₄ modification and Pt loading. It is proposed that ZnFe₂O₄ does not function as visible light sensitizer but as oxidation active sites. In the present ZnFe₂O₄/g-C ₃N₄ photocatalysts, the photo-induced holes in g-C ₃N₄ tend to transfer to ZnFe₂O₄ due to the straddling band structures (Type I band alignment), while the photo-induced electrons in g-C₃N₄ prefer to transfer to the loaded Pt cocatalysts, which can function as reduction active sites for hydrogen production. As a result, the photoinduced electrons and holes in g-C₃N₄ are efficiently separated by spatial engineering of the photo-active sites, and hence enhanced photocatalytic hydrogen generation activity is obtained.