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.