Tin-grafted TiO₂ with enhanced activity for photocatalytic hydrogen generation from aqueous methanol solutions

A series of Sn-modified TiO₂ samples was prepared by an anhydrous grafting route and applied in the photocatalytic H₂ evolution from aqueous methanol solutions. The synthesized samples were characterized by N₂ physisorption, X-ray diffraction, Raman, UV-Vis reflectance and photoluminescence spectroscopy. The results revealed that the tin species were highly dispersed on the TiO₂ surface and did not alter its crystalline structure. Photocatalytic results showed that Sn-grafting led to a significant improvement in the activity compared to bare TiO₂ owing to the improved charge separation. The photocatalytic performance of samples was found to depend highly on the Sn content. Additionally, the influence of Rh co-modification on the photocatalytic activity of Sn-grafted TiO₂ was investigated, and a synergetic effect between Sn and Rh was identified, which is attributed to the assumed electron relay among TiO₂, tin species and photodeposited Rh nanoparticles.