Importance of the tuning of band position in optimizing the electronic coupling and photocatalytic activity of nanocomposite

Abstract The electronic coupling and photocatalytic activity of Ag₂CO₃-TiO₂ nanocomposite can be optimized by the fine-tuning of the band position of titanium oxide with nitrogen doping. The increase of the valence band energy of TiO₂ by N-doping leads not only to the enhanced absorption of visible light but also to the promoted hole transfer from Ag₂CO₃ to TiO₂, resulting in the efficient spatial separation of photogenerated electrons and holes. While the undoped Ag₂CO₃-TiO₂ nanocomposite shows an inferior photocatalytic activity to the pure Ag₂CO₃, the photocatalyst performance of N-doped nanocomposite is better than those of Ag₂CO₃ and undoped Ag₂CO₃-TiO₂ nanocomposite. This observation underscores a significant enhancement of the photocatalytic activity of nanocomposite upon N-doping, a result of enhanced electronic coupling between the hybridized species. The present results clearly demonstrate the importance of the fine-tuning of band position in optimizing the photocatalytic activity of hybrid-type photocatalysts.