Facile one-step synthesis of TiO 2 /Ag/SnO 2 ternary heterostructures with enhanced visible light photocatalytic activity.

Novel TiO2 /Ag/SnO2 composites were successfully prepared by a facile one-step reduction approach using stannous chloride as both SnO2 precursor and reducing agent. The Ag nanoparticles with sizes of 2.04-3.94 nm were located on TiO2 matrix and immobilized by the surrounded SnO2 . The resulted TiO2 /Ag/SnO2 nanocomposites were used as photocatalyst for photodegradation of methylene blue under visible light. The experimental results demonstrated that the visible light photocatalytic activity of the TiO2 /Ag/SnO2 was significantly enhanced in comparison with the individual TiO2 or the binary composite (TiO2 /Ag or TiO2 /SnO2 ) and the degradation rate was up to about 9.5 times that of commercial TiO2 . The photocatalytic activity of the TiO2 /Ag/SnO2 composites could be well controlled by simply tuning the dosages of Ag precursor and the optimized activity of the composites was obtained when the dosage of Ag precursor was 2%. Moreover, the TiO2 /Ag/SnO2 photocatalyst exhibited high stability for degradation of methylene blue even after four successive cycles.