Biotemplated synthesis of Au loaded Sn-doped TiO2 hierarchical nanorods using nanocrystalline cellulose and their applications in photocatalysis

Sn doped TiO2 (SDT) hierarchical nanorods have been synthesized by using nanocystalline cellulose nanorod as biotemplate. Experimental results show that the phase transition from anatase to rutile can be realized by increasing the calcination temperature. In contrast to enhancing the calcination temperature, the Sn doping can more effectively improve the phase transition with remaining morphology due to the similar ionic radius and charge between Sn and Ti. The crystallinity, electronic structure, interface charge transfer process, and the specific surface area have a strong effect on the photocatalytic activity of the hierarchical TiO2 and SDT nanorods. Furthermore, the photocatalytic activity of SDT hierarchical nanorods can be obviously improved by loaded Au nanoparticles on the surface due to the local surface plasmon resonance effect of Au and formation of a Schottky barrier at the Au/TiO2 interface, which is in favor of the effective separation of photoinduced carriers and the formation of superoxide anion radicals.