The roles of surface-doped metal ions (V, Mn, Fe, Cu, Ce, and W) in the interfacial behavior of TiO2 photocatalysts

- Surface-doped Fe, Cu, and V ions improve photocatalytic activity, whereas Mn, Ce, and W ions cause adverse effects.
- The energy states and the Lewis acidic strength of doped ions determine their roles in the charge utilization.
- Suitable dopants provide alternative pathways for interfacial charge transfer.
- Unsuitable dopants impede interfacial charge transfer and promote annihilation.