One-pot solvothermal syntheses of ternary heterostructured TiO2-Bi2MoO6/Bi3.64Mo0.36O6.55 controllable in terms of composition, morphology and structure: Materials of high visible-light driven photocatalytic activity

Novel ternary heterostructured TiO2-Bi2MoO6/Bi3.64Mo0.36O6.55 were synthesized by a one-pot template-free solvothermal method. For comparison studies, Bi2MoO6, Bi3.64Mo0.36O6.55, Bi2MoO6/Bi3.64Mo0.36O6.55, TiO2-Bi2MoO6, and TiO2-Bi3.64Mo0.36O6.55 were also synthesized likewise. The photocatalysts were characterized by powder X-ray diffraction, UV-vis diffuse reflectance spectroscopy, scanning electron microscopy, transmission electron microscopy, and Raman spectroscopy. The experimental results showed that the composition, morphology and structure of the photocatalysts can be well controlled by adjusting the pH value, alcohol/water ratio, and TiO2 content. Based on the findings, we put forward a mechanism for the formation of the materials. Furthermore, the results of photocatalytic degradation of Rhodamine B (RhB) and o-nitrophenol over the as-prepared materials indicate that photocatalytic efficiency can be closely related to the composition, morphology and structure of the materials. The ternary heterostructured 5%TiO2-Bi2MoO6/Bi3.64Mo0.36O6.55 exhibits good visible-light driven photocatalytic activity in the degradation of RhB and o-nitrophenol, much higher than those of TiO2, Bi2MoO6, Bi3.64Mo0.36O6.55, and any combination of the three. Finally, a new mechanism for the photocatalytic action of the heterostructured materials was put forward. Overall, the investigation provides a new reaction mode to explain the effective interfacial charge transfer and the significant improvement in photocatalytic efficiency of the ternary heterostructured composites. (C) 2013 Published by Elsevier B.V.