Synthesis and Photocatalytic Properties of SnO2-Mixed and Sn-Doped TiO2 Nanoparticles

Abstract

-mixed and Sn-doped nanoparticles were synthesized via a hydrothermal process. -mixed nanoparticles prepared in a neutral condition consisted of anatase nanoparticles(diamond shape, ~25 nm) and cassiterite nanoparticles(spherical shape, ~10 nm). On the other hand, Sn-doped nanoparticles obtained under a high acidic condition showed a crystalline phase corresponding to rutile . As the Sn content increased, the particle shape changed from rod-like(d~40 nm, 1~200 nm) to spherical(18 nm) with a decrease in the particle size. The peak shift in the XRD results and a change of the c-axis lattice parameter with the Sn content demonstrate that the in the rutile phase was doped with Sn. The photocatalytic activity of the -mixed nanoparticles dramatically increased and then decreased when the content exceeded 4%. The increased photocatalytic activity is mainly attributed to the improved charge separation of the nanoparticles with the . In the case of Sn-doped nanoparticles, the photocatalytic activity increased slightly with the Sn content due most likely to the larger energy bandgap caused by Sn-doping and the decrease in the particle size. The -mixed nanoparticles generally exhibited higher photocatalytic activity than the Sn-doped nanoparticles. This was caused by the phase difference of .